Role of BRCA1 in Controlling Mitotic Arrest in Ovarian Cystadenoma Cells

PubMed Central

Yu, Vanessa M.; Marion, Christine M.; Austria, Theresa M.; Yeh, Jennifer; Schönthal, Axel H.; Dubeau, Louis

2011-01-01

Cancers that develop in BRCA1 mutation carriers are usually near tetraploid/polyploid. This led us to hypothesize that BRCA1 controls the mitotic checkpoint complex, as loss of such control could lead to mitotic errors resulting in tetraploidy/polyploidy with subsequent aneuploidy. We used an in vitro system mimicking pre-malignant conditions, consisting of cell strains derived from the benign counterparts of serous ovarian carcinomas (cystadenomas) and expressing SV40 large T antigen, conferring the equivalent of a p53 mutation. We previously showed that such cells undergo one or several doublings of their DNA content as they age in culture and approach the phenomenon of in vitro crisis. Here we show that such increase in DNA content reflects a cell cycle arrest possibly at the anaphase promoting complex, as evidenced by decreased BrdU incorporation and increased expression of the mitotic checkpoint complex. Down-regulation of BRCA1 in cells undergoing crisis leads to activation of the anaphase promoting complex and resumption of growth kinetics similar to those seen in cells before they reach crisis. Cells recovering from crisis after BRCA1 down-regulation become multinucleated, suggesting that reduced BRCA1 expression may lead to initiation of a new cell cycle without completion of cytokinesis. This is the first demonstration that BRCA1 controls a physiological arrest at the M phase apart from its established role in DNA damage response, a role that could represent an important mechanism for acquisition of aneuploidy during tumor development. This may be particularly relevant to cancers that have a near tetraploid/polyploid number of chromosomes. PMID:21792894

Small tyrosine kinase inhibitors interrupt EGFR signaling by interacting with erbB3 and erbB4 in glioblastoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carrasco-Garcia, Estefania; Saceda, Miguel; Unidad de Investigacion, Hospital General Universitario de Elche, 03203 Elche

Signaling through the epidermal growth factor receptor (EGFR) is relevant in glioblastoma. We have determined the effects of the EGFR inhibitor AG1478 in glioblastoma cell lines and found that U87 and LN-229 cells were very sensitive to this drug, since their proliferation diminished and underwent a marked G{sub 1} arrest. T98 cells were a little more refractory to growth inhibition and A172 cells did not undergo a G{sub 1} arrest. This G{sub 1} arrest was associated with up-regulation of p27{sup kip1}, whose protein turnover was stabilized. EGFR autophosphorylation was blocked with AG1478 to the same extent in all the cellmore » lines. Other small-molecule EGFR tyrosine kinase inhibitors employed in the clinic, such as gefitinib, erlotinib and lapatinib, were able to abrogate proliferation of glioblastoma cell lines, which underwent a G{sub 1} arrest. However, the EGFR monoclonal antibody, cetuximab had no effect on cell proliferation and consistently, had no effect on cell cycle either. Similarly, cetuximab did not inhibit proliferation of U87 {Delta}EGFR cells or primary glioblastoma cell cultures, whereas small-molecule EGFR inhibitors did. Activity of downstream signaling molecules of EGFR such as Akt and especially ERK1/2 was interrupted with EGFR tyrosine kinase inhibitors, whereas cetuximab treatment could not sustain this blockade over time. Small-molecule EGFR inhibitors were able to prevent phosphorylation of erbB3 and erbB4, whereas cetuximab only hindered EGFR phosphorylation, suggesting that EGFR tyrosine kinase inhibitors may mediate their anti-proliferative effects through other erbB family members. We can conclude that small-molecule EGFR inhibitors may be a therapeutic approach for the treatment of glioblastoma patients.« less

Modulation of Medium pH by Caulobacter crescentus Facilitates Recovery from Uranium-Induced Growth Arrest

PubMed Central

Park, Dan M.

2014-01-01

The oxidized form of uranium [U(VI)] predominates in oxic environments and poses a major threat to ecosystems. Due to its ability to mineralize U(VI), the oligotroph Caulobacter crescentus is an attractive candidate for U(VI) bioremediation. However, the physiological basis for U(VI) tolerance is unclear. Here we demonstrated that U(VI) caused a temporary growth arrest in C. crescentus and three other bacterial species, although the duration of growth arrest was significantly shorter for C. crescentus. During the majority of the growth arrest period, cell morphology was unaltered and DNA replication initiation was inhibited. However, during the transition from growth arrest to exponential phase, cells with shorter stalks were observed, suggesting a decoupling between stalk development and the cell cycle. Upon recovery from growth arrest, C. crescentus proliferated with a growth rate comparable to that of a control without U(VI), although a fraction of these cells appeared filamentous with multiple replication start sites. Normal cell morphology was restored by the end of exponential phase. Cells did not accumulate U(VI) resistance mutations during the prolonged growth arrest, but rather, a reduction in U(VI) toxicity occurred concomitantly with an increase in medium pH. Together, these data suggest that C. crescentus recovers from U(VI)-induced growth arrest by reducing U(VI) toxicity through pH modulation. Our finding represents a unique U(VI) detoxification strategy and provides insight into how microbes cope with U(VI) under nongrowing conditions, a metabolic state that is prevalent in natural environments. PMID:25002429

G1 arrest induction represents a critical determinant for cisplatin cytotoxicity in G1 checkpoint-retaining human cancers.

PubMed

Un, Frank

2007-04-01

Cisplatin has been used effectively to treat various human cancer types; yet, the precise mechanism underlying its cytotoxicity remains unknown. In eukaryotes, progression through G1 is monitored by a checkpoint, which executes G1 arrest in the event of DNA damage to allow time for repair before initiating DNA replication. The retinoblastoma tumor suppressor gene is an integral component of the mammalian G1 checkpoint. The utility of the retinoblastoma gene as a therapeutic for human cancers has been investigated. Intriguingly, the cytotoxicity profile of the retinoblastoma gene therapy closely parallels the clinical targets of cisplatin. It prompted an investigation into the potential role of the checkpoint-induced G1 arrest in cisplatin cytotoxicity. Here, the evidence that G1 arrest induction represents a critical step in cisplatin-induced lytic path is presented. First, cisplatin-treated human cancer cells undergo a prolonged G1 arrest before dying. Second, triggering G1 arrest via infection with a recombinant adenovirus expressing the human retinoblastoma gene is sufficient to potentiate lethality in the absence of cisplatin. Third, the extent of the lethality induced correlates with the G1-arresting potential of the ectopically expressed human retinoblastoma polypeptide. Fourth, human cancer cells resistant to cisplatin do not undergo G1 arrest despite cisplatin treatment. The above mechanism may be exploited to develop therapeutics that preserve the efficacy of cisplatin yet bypass its mutagenicity associated with the formation of secondary tumors.

Myeloblastic leukemia cells conditionally blocked by myc-estrogen receptor chimeric transgenes for terminal differentiation coupled to growth arrest and apoptosis.

PubMed

Selvakumaran, M; Liebermann, D; Hoffman-Liebermann, B

1993-05-01

Conditional mutants of the myeloblastic leukemic M1 cell line, expressing the chimeric mycer transgene, have been established. It is shown that M1 mycer cells, like M1, undergo terminal differentiation coupled to growth arrest and programmed cell death (apoptosis) after treatment with the physiologic differentiation inducer interleukin-6. However, when beta-estradiol is included in the culture medium, M1 mycer cells respond to differentiation inducers like M1 myc cell lines, where the differentiation program is blocked at an intermediate stage. By manipulating the function of the mycer transgene product, it is shown that there is a 10-hour window during myeloid differentiation, from 30 to 40 hours after the addition of the differentiation inducer, when the terminal differentiation program switches from being dependent on c-myc suppression to becoming c-myc suppression independent, where activation of c-myc has no apparent effect on mature macrophages. M1 mycer cell lines provide a powerful tool to increase our understanding of the role of c-myc in normal myelopoiesis and in leukemogenesis, also providing a strategy to clone c-myc target genes.

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.

Sequential signaling cascade of IL-6 and PGC-1α is involved in high glucose-induced podocyte loss and growth arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong Il; Park, Soo Hyun, E-mail: parksh@chonnam.ac.kr

Highlights: •The pathophysiological role of IL-6 in high glucose-induced podocyte loss. •The novel role of PGC-1α in the development of diabetic nephropathy. •Signaling of IL-6 and PGC-1α in high glucose-induced dysfunction of podocyte. -- Abstract: Podocyte loss, which is mediated by podocyte apoptosis, is implicated in the onset of diabetic nephropathy. In this study, we investigated the involvement of interleukin (IL)-6 in high glucose-induced apoptosis of rat podocytes. We also examined the pathophysiological role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) in this system. High glucose treatment induced not only podocyte apoptosis but also podocyte growth arrest. High glucosemore » treatment also increased IL-6 secretion and activated IL-6 signaling. The high glucose-induced podocyte apoptosis was blocked by IL-6 neutralizing antibody. IL-6 treatment or overexpression induced podocyte apoptosis and growth arrest, and IL-6 siRNA transfection blocked high glucose-induced podocyte apoptosis and growth arrest. Furthermore, high glucose or IL-6 treatment increased PGC-1α expression, and PGC-1α overexpression also induced podocyte apoptosis and growth arrest. PGC-1α siRNA transfection blocked high glucose-induced podocyte apoptosis and growth arrest. Collectively, these findings showed that high glucose promoted apoptosis and cell growth arrest in podocytes via IL-6 signaling. In addition, PGC-1α is involved in podocyte apoptosis and cell growth arrest. Therefore, blocking IL-6 and its downstream mediators such as IL6Rα, gp130 and PGC-1α may attenuate the progression of diabetic nephropathy.« less

Characterization of the cellular and antitumor effects of MPI-0479605, a small-molecule inhibitor of the mitotic kinase Mps1.

PubMed

Tardif, Keith D; Rogers, Aaron; Cassiano, Jared; Roth, Bruce L; Cimbora, Daniel M; McKinnon, Rena; Peterson, Ashley; Douce, Thomas B; Robinson, Rosann; Dorweiler, Irene; Davis, Thaylon; Hess, Mark A; Ostanin, Kirill; Papac, Damon I; Baichwal, Vijay; McAlexander, Ian; Willardsen, J Adam; Saunders, Michael; Christophe, Hoarau; Kumar, D Vijay; Wettstein, Daniel A; Carlson, Robert O; Williams, Brandi L

2011-12-01

Mps1 is a dual specificity protein kinase that is essential for the bipolar attachment of chromosomes to the mitotic spindle and for maintaining the spindle assembly checkpoint until all chromosomes are properly attached. Mps1 is expressed at high levels during mitosis and is abundantly expressed in cancer cells. Disruption of Mps1 function induces aneuploidy and cell death. We report the identification of MPI-0479605, a potent and selective ATP competitive inhibitor of Mps1. Cells treated with MPI-0479605 undergo aberrant mitosis, resulting in aneuploidy and formation of micronuclei. In cells with wild-type p53, this promotes the induction of a postmitotic checkpoint characterized by the ATM- and RAD3-related-dependent activation of the p53-p21 pathway. In both wild-type and p53 mutant cells lines, there is a growth arrest and inhibition of DNA synthesis. Subsequently, cells undergo mitotic catastrophe and/or an apoptotic response. In xenograft models, MPI-0479605 inhibits tumor growth, suggesting that drugs targeting Mps1 may have utility as novel cancer therapeutics.

Transforming Growth Factor-β1 activates ΔNp63/c-Myc to promote Oral Squamous cell carcinoma

PubMed Central

Hu, Lihua; Li, Zhi; Liu, Jingpeng; Wang, Chunling; Nawshad, Ali

2016-01-01

Objective During the development of oral squamous cell carcinoma (OSCC), the transformed epithelial cells undergo increased proliferation resulting in tumor growth and invasion. Interestingly, throughout all phases of differentiation and progression of OSCC, TGFβ1 induces cell cycle arrest/apoptosis, however; the role of TGFβ1 in promoting cancer cell proliferation has not been explored in detail. The purpose of this study was to identify the effect of TGFβ1 on OSCC cell proliferation. Methods Using both human OSCC samples and cell lines (UMSCC38 and UMSCC 11B), we employed biochemical experiments to show protein, mRNA, gene expression and protein-DNA interactions during OSCC progression. Results Our results showed that TGFβ1 increased OSCC cell proliferation by up-regulating the expression of ΔNp63 and c-Myc oncogenes. While the basal OSCC cell proliferation is sustained by activating ΔNp63, increased induction of c-Myc causes unregulated OSCC cell proliferation. Following induction of the cell cycle by ΔNp63 and c-Myc, cancer cells that halt c-Myc activity undergo EMT/invasion while those that continue to express ΔNp63/c-Myc undergo unlimited progression through the cell cycle. Conclusion We conclude that OSCC proliferation is manifested by the induction of c-Myc in response to TGFβ1 signaling, which is essential for OSCC growth. Our data highlights the potential role of TGFβ1 in the induction of cancer progression and invasion of OSCC. PMID:27567435

Growth arrest despite growth hormone replacement, post-craniopharyngioma surgery.

PubMed Central

DeVile, C J; Hayward, R D; Neville, B G; Grant, D B; Stanhope, R

1995-01-01

Children with growth failure, whether secondary to an endocrinopathy such as growth hormone deficiency or secondary to neurological handicap with poor nutrient intake, grow at a subnormal rate but it is most unusual for a child to have complete growth arrest. PMID:7745571

Material-induced Senescence (MIS): Fluidity Induces Senescent Type Cell Death of Lung Cancer Cells via Insulin-Like Growth Factor Binding Protein 5.

PubMed

Mano, Sharmy Saimon; Uto, Koichiro; Ebara, Mitsuhiro

2017-01-01

Objective: We propose here material-induced senescence (MIS) as a new therapeutic concept that limits cancer progression by stable cell cycle arrest. This study examined for the first time the effect of material fluidity on cellular senescence in lung carcinoma using poly(ε-caprolactone- co -D, L-lactide) (P(CL- co -DLLA)) with tunable elasticity and fluidity. Methods: The fluidity was varied by chemically crosslinking the polymer networks: the crosslinked P(CL- co -DLLA) shows solid-like properties with a stiffness of 260 kPa, while the non-crosslinked polymer exists in a quasi-liquid state with loss and storage moduli of 33 kPa and 11 kPa, respectively. Results: We found that cancer cells growing on the non-crosslinked, fluidic substrate undergo a non-apoptotic form of cell death and the cell cycle was accumulated in a G0/G1 phase. Next, we investigated the expression of biomarkers that are associated with cancer pathways. The cancer cells on the fluidic substrate expressed several biomarkers associated with senescence such as insulin-like growth factor binding protein 5 (IGFBP5). This result indicates that when cancer cells sense fluidity in their surroundings, the cells express IGFBP5, which in turn triggers the expression of tumor suppressor protein 53 and initiates cell cycle arrest at the G1 phase followed by cellular senescence. Furthermore, the cancer cells on the fluidic substrate maintained their epithelial phenotype, suggesting that the cancer cells do not undergo epithelial to mesenchymal transition. Conclusion: By considering these results as the fundamental information for MIS, our system could be applied to induce senescence in treatment-resistant cancers such as metastatic cancer or cancer stem cells.

Premature aging/senescence in cancer cells facing therapy: good or bad?

PubMed

Gonzalez, Llilians Calvo; Ghadaouia, Sabrina; Martinez, Aurélie; Rodier, Francis

2016-02-01

Normal and cancer cells facing their demise following exposure to radio-chemotherapy can actively participate in choosing their subsequent fate. These programmed cell fate decisions include true cell death (apoptosis-necroptosis) and therapy-induced cellular senescence (TIS), a permanent "proliferative arrest" commonly portrayed as premature cellular aging. Despite a permanent loss of proliferative potential, senescent cells remain viable and are highly bioactive at the microenvironment level, resulting in a prolonged impact on tissue architecture and functions. Cellular senescence is primarily documented as a tumor suppression mechanism that prevents cellular transformation. In the context of normal tissues, cellular senescence also plays important roles in tissue repair, but contributes to age-associated tissue dysfunction when senescent cells accumulate. Theoretically, in multi-step cancer progression models, cancer cells have already bypassed cellular senescence during their immortalization step (see hallmarks of cancer). It is then perhaps surprising to find that cancer cells often retain the ability to undergo TIS, or premature aging. This occurs because cellular senescence results from multiple signalling pathways, some retained in cancer cells, aiming to prevent cell cycle progression in damaged cells. Since senescent cancer cells persist after therapy and secrete an array of cytokines and growth factors that can modulate the tumor microenvironment, these cells may have beneficial and detrimental effects regarding immune modulation and survival of remaining proliferation-competent cancer cells. Similarly, while normal cells undergoing senescence are believed to remain indefinitely growth arrested, whether this is true for senescent cancer cells remains unclear, raising the possibility that these cells may represent a reservoir for cancer recurrence after treatment. This review discusses our current knowledge on cancer cell senescence and highlight questions that must be addressed to fully understand the beneficial and detrimental impacts of cellular senescence during cancer therapy.

Cardiac Emergencies in Neurosurgical Patients

PubMed Central

Petropolis, Andrea; Cappellani, Ronald B.

2015-01-01

Perioperative safety concerns are a major area of interest in recent years. Severe cardiac perturbation such as cardiac arrest is one of the most dreaded complications in the intraoperative period; however, little is known about the management of these events in the patients undergoing elective neurosurgery. This special group needs further attention, as it is often neither feasible nor appropriate to apply conventional advanced cardiac life support algorithms in patients undergoing neurosurgery. Factors such as neurosurgical procedure and positioning can also have a significant effect on the occurrence of cardiac arrest. Therefore, the aim of this paper is to describe the various causes and management of cardiac emergencies with special reference to cardiac arrest during elective neurosurgical procedures, including discussion of position-related factors and resuscitative considerations in these situations. This will help to formulate possible guidelines for management of such events. PMID:25692145

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

Muscle Contraction Arrests Tumor Growth

DTIC Science & Technology

2006-09-01

AD_________________ Award Number: W81XWH-05-1-0464 TITLE: Muscle Contraction Arrests Tumor Growth...DATE 01-09-2006 2. REPORT TYPE Annual 3. DATES COVERED 1 Sep 2005 – 31 Aug 2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Muscle ... Contraction Arrests Tumor Growth 5b. GRANT NUMBER W81XWH-05-1-0464 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kim Westerlind, Ph.D. 5d. PROJECT NUMBER

Cell Death During Crisis Is Mediated by Mitotic Telomere Deprotection

PubMed Central

Hayashi, Makoto T.; Cesare, Anthony J.; Rivera, Teresa; Karlseder, Jan

2015-01-01

Tumour formation is blocked by two barriers, replicative senescence and crisis1. Senescence is triggered by short telomeres and is bypassed by disruption of tumour suppressive pathways. After senescence bypass, cells undergo crisis, during which almost all of the cells in the population die. Cells that escape crisis harbor unstable genomes and other parameters of transformation. The mechanism of cell death during crisis remained elusive. We show that cells in crisis undergo spontaneous mitotic arrest, resulting in death during mitosis or in the following cell cycle. The phenotype was induced by loss of p53 function, and suppressed by telomerase overexpression. Telomere fusions triggered mitotic arrest in p53-compromised non-crisis cells, indicating such fusions as the underlying cause. Exacerbation of mitotic telomere deprotection by partial TRF2 knockdown2 increased the ratio of cells that died during mitotic arrest and sensitized cancer cells to mitotic poisons. We propose a crisis pathway wherein chromosome fusions induce mitotic arrest, resulting in mitotic telomere deprotection and cell death, thereby eliminating precancerous cells from the population. PMID:26108857

Transition of intestinal fatty acid-binding protein on hypothermic circulatory arrest with cardiopulmonary bypass.

PubMed

Kano, Hiroya; Takahashi, Hiroaki; Inoue, Takeshi; Tanaka, Hiroshi; Okita, Yutaka

2017-04-01

Intestinal fatty acid-binding protein (I-FABP) is increasingly employed as a highly specific marker of intestinal necrosis. However, the value of this marker associated with cardiovascular surgery with hypothermic circulatory arrest is unclear. The aim of this study was to measure serum I-FABP levels and provide the transition of I-FABP levels with hypothermic circulatory arrest to help in the management of intestinal perfusion. From August 2011 to September 2013, 33 consecutive patients who had aortic arch surgery with hypothermic circulatory arrest or heart valve surgery performed were enrolled in the study. Twenty patients had aortic surgery with hypothermic (23-29°C) circulatory arrest and 13 patients had heart valve surgery with cardiopulmonary bypass (33°C). I-FABP levels increased, both in patients undergoing aortic surgery with hypothermic circulatory arrest and heart valve surgery with cardiopulmonary bypass, reaching peak levels shortly after the administration of protamine. I-FABP levels in patients with aortic surgery were significantly higher with circulatory arrest. They reached peak levels immediately after recirculation and there was a significant drop at the end of surgery (p<0.001). I-FABP levels in heart valve surgery were gradually increased, with the highest at the administration of protamine; they gradually decreased. Peak I-FABP levels were significantly higher in patients undergoing aortic surgery with hypothermic circulatory arrest than in patients with heart valve surgery. However, no postoperative reperfusion injury occurred in the intestinal tract due to the use of hypothermic organ protection. Plasma I-FABP monitoring could be a valuable method for finding an intestinal ischemia in patients with cardiovascular surgery.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokota, Shin-ichi; Okabayashi, Tamaki; Fujii, Nobuhiro, E-mail: fujii@sapmed.ac.j

2011-05-25

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

Melanocytic nevi and melanoma: unraveling a complex relationship

PubMed Central

Damsky, WE; Bosenberg, M

2018-01-01

Approximately 33% of melanomas are derived directly from benign, melanocytic nevi. Despite this, the vast majority of melanocytic nevi, which typically form as a result of BRAFV600E-activating mutations, will never progress to melanoma. Herein, we synthesize basic scientific insights and data from mouse models with common observations from clinical practice to comprehensively review melanocytic nevus biology. In particular, we focus on the mechanisms by which growth arrest is established after BRAFV600E mutation. Means by which growth arrest can be overcome and how melanocytic nevi relate to melanoma are also considered. Finally, we present a new conceptual paradigm for understanding the growth arrest of melanocytic nevi in vivo termed stable clonal expansion. This review builds upon the canonical hypothesis of oncogene-induced senescence in growth arrest and tumor suppression in melanocytic nevi and melanoma. PMID:28604751

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

PubMed

Wang, Tao; Xie, Zi-ping; Huang, Zhan-sen; Li, Hao; Wei, An-yang; Di, Jin-ming; Xiao, Heng-jun; Zhang, Zhi-gang; Cai, Liu-hong; Tao, Xin; Qi, Tao; Chen, Di-ling; Chen, Jun

2015-10-01

In this study, one immortalized human normal prostatic epithelial cell line (BPH) and four human prostate cancer cell lines (LNCaP, 22Rv1, PC-3, and DU-145) were treated with Ganoderma Lucidum triterpenoids (GLT) at different doses and for different time periods. Cell viability, apoptosis, and cell cycle were analyzed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR and Western blotting. It was found that GLT dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. GLT-induced apoptosis was due to activation of Caspases-9 and -3 and turning on the downstream apoptotic events. GLT-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and E2F1 expression at the late time. These findings demonstrate that GLT suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which might suggest that GLT or Ganoderma Lucidum could be used as a potential therapeutic drug for prostate cancer.

The Cell Cycle Inhibitor p27KIP1: A Key Mediator of G1 Arrest by Androgen Ablation an dby Vitamin D3 Analog

DTIC Science & Technology

2000-02-01

al., 1996; Tyers, 1996). gland . Higher doses of androgen cause growth arrest by p27 increases during differentiation in many cell inducing...innocuous hormones in human prostate cancer patients. These vitamin D3 analogs can inhibit prostate cancer growth and yet they do not cause the negative side...Vitamin D3 and a physiologic does of DHT could cause a synergistic growth arrest in prostate cancer cells (22). The vitamin D3 analogue EB 1089 has the

As seen on TV: observational study of cardiopulmonary resuscitation in British television medical dramas

PubMed Central

Gordon, P N; Williamson, S; Lawler, P G

1998-01-01

Objective: To determine the frequency and accuracy with which cardiopulmonary resuscitation is portrayed in British television medical dramas. Design: Observational study. Subjects: 64 episodes of three major British television medical dramas: Casualty, Cardiac Arrest, and Medics. Main outcome measures: Frequency of cardiopulmonary resuscitation shown on television; age, sex, and diagnosis of the patients undergoing resuscitation; rate of survival through resuscitation. Results: Overall 52 patients had a cardiorespiratory arrest on screen and 3 had a respiratory arrest alone, all the arrests occurring in 40 of the 64 episodes. Of the 52 patients having cardiorespiratory arrest, 32 (62%) underwent an attempt at cardiopulmonary resuscitation; 8 attempts were successful. All 3 of the patients having respiratory arrests alone received ventilatory support and survived. On 48% of occasions, victims of cardiac arrest seemed to be less than 35 years old. Conclusions: Cardiorespiratory resuscitation is often depicted in British television medical dramas. Patients portrayed receiving resuscitation are likely to be in a younger age group than in real life. Though the reasons for resuscitation are more varied and more often associated with trauma than in reality, the overall success rate is nevertheless realistic. Widespread overoptimism of patients for survival after resuscitation cannot necessarily be blamed on British television medical dramas. Key messagesA quarter of patients in British television medical dramas who received cardiopulmonary resuscitation on screen seemed to surviveThis figure is comparable to initial survival rates in a series of patients in real lifePatients on television are more likely to suffer cardiac arrest as a result of trauma than in real life, and patients undergoing resuscitation are likely to be younger than patients in real lifeThe overall survival rate of patients after cardiopulmonary resuscitation in British television medical drama seems to be more realistic than in American medical dramas PMID:9740563

RNase alleviates neurological dysfunction in mice undergoing cardiac arrest and cardiopulmonary resuscitation

PubMed Central

Ma, Ye; Chen, Chan; Zhang, Shu; Wang, Qiao; Chen, Hai; Dong, Yuanlin; Zhang, Zheng; Li, Yan; Niu, Zhendong; Zhu, Tao; Yu, Hai; Liu, Bin

2017-01-01

Cardiac arrest (CA) is one of the leading lethal factors. Despite cardiopulmonary resuscitation (CPR) procedure has been consecutively improved and lots of new strategies have been developed, neurological outcome of the patients experienced CPR is still disappointing. Ribonuclease (RNase) has been demonstrated to have neuroprotective effects in acute stroke and postoperative cognitive impairment, possibly through acting against endogenous RNA that released from damaged tissue. However, the role of RNase in post-cardiac arrest cerebral injury is unknown. In the present study, we investigated the role of RNase in neurological outcome of mice undergoing 5 minutes of CA and followed by CPR. RNase or the same dosage of normal saline was administrated. We found that RNase administration could: 1) improve neurologic score on day 1 and day 3 after CA/CPR performance; 2) improve memory and learning ability on day 3 after training in contextual fear-conditioning test; 3) reduce extracellular RNA (exRNA) level in plasma and hippocampus tissue, and hippocampal cytokines mRNA production on day 3 after CA/CPR procedure; 4) attenuate autophagy levels in hippocampus tissue on day 3 after CA/CPR procedure. In conclusion, RNase could improve neurological function by reducing inflammation response and autophagy in mice undergoing CA/CPR. PMID:28881795

Natural Variation in Small Molecule–Induced TIR-NB-LRR Signaling Induces Root Growth Arrest via EDS1- and PAD4-Complexed R Protein VICTR in Arabidopsis[C][W

PubMed Central

Kim, Tae-Houn; Kunz, Hans-Henning; Bhattacharjee, Saikat; Hauser, Felix; Park, Jiyoung; Engineer, Cawas; Liu, Amy; Ha, Tracy; Parker, Jane E.; Gassmann, Walter; Schroeder, Julian I.

2012-01-01

In a chemical genetics screen we identified the small-molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) that triggers rapid inhibition of early abscisic acid signal transduction via PHYTOALEXIN DEFICIENT4 (PAD4)- and ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)-dependent immune signaling mechanisms. However, mechanisms upstream of EDS1 and PAD4 in DFPM-mediated signaling remain unknown. Here, we report that DFPM generates an Arabidopsis thaliana accession-specific root growth arrest in Columbia-0 (Col-0) plants. The genetic locus responsible for this natural variant, VICTR (VARIATION IN COMPOUND TRIGGERED ROOT growth response), encodes a TIR-NB-LRR (for Toll-Interleukin1 Receptor–nucleotide binding–Leucine-rich repeat) protein. Analyses of T-DNA insertion victr alleles showed that VICTR is necessary for DFPM-induced root growth arrest and inhibition of abscisic acid–induced stomatal closing. Transgenic expression of the Col-0 VICTR allele in DFPM-insensitive Arabidopsis accessions recapitulated the DFPM-induced root growth arrest. EDS1 and PAD4, both central regulators of basal resistance and effector-triggered immunity, as well as HSP90 chaperones and their cochaperones RAR1 and SGT1B, are required for the DFPM-induced root growth arrest. Salicylic acid and jasmonic acid signaling pathway components are dispensable. We further demonstrate that VICTR associates with EDS1 and PAD4 in a nuclear protein complex. These findings show a previously unexplored association between a TIR-NB-LRR protein and PAD4 and identify functions of plant immune signaling components in the regulation of root meristematic zone-targeted growth arrest. PMID:23275581

The Forkhead Transcription Factor FOXP2 Is Required for Regulation of p21WAF1/CIP1 in 143B Osteosarcoma Cell Growth Arrest.

PubMed

Gascoyne, Duncan M; Spearman, Hayley; Lyne, Linden; Puliyadi, Rathi; Perez-Alcantara, Marta; Coulton, Les; Fisher, Simon E; Croucher, Peter I; Banham, Alison H

2015-01-01

Mutations of the forkhead transcription factor FOXP2 gene have been implicated in inherited speech-and-language disorders, and specific Foxp2 expression patterns in neuronal populations and neuronal phenotypes arising from Foxp2 disruption have been described. However, molecular functions of FOXP2 are not completely understood. Here we report a requirement for FOXP2 in growth arrest of the osteosarcoma cell line 143B. We observed endogenous expression of this transcription factor both transiently in normally developing murine osteoblasts and constitutively in human SAOS-2 osteosarcoma cells blocked in early osteoblast development. Critically, we demonstrate that in 143B osteosarcoma cells with minimal endogenous expression, FOXP2 induced by growth arrest is required for up-regulation of p21WAF1/CIP1. Upon growth factor withdrawal, FOXP2 induction occurs rapidly and precedes p21WAF1/CIP1 activation. Additionally, FOXP2 expression could be induced by MAPK pathway inhibition in growth-arrested 143B cells, but not in traditional cell line models of osteoblast differentiation (MG-63, C2C12, MC3T3-E1). Our data are consistent with a model in which transient upregulation of Foxp2 in pre-osteoblast mesenchymal cells regulates a p21-dependent growth arrest checkpoint, which may have implications for normal mesenchymal and osteosarcoma biology.

The Forkhead Transcription Factor FOXP2 Is Required for Regulation of p21WAF1/CIP1 in 143B Osteosarcoma Cell Growth Arrest

PubMed Central

Gascoyne, Duncan M.; Spearman, Hayley; Lyne, Linden; Puliyadi, Rathi; Perez-Alcantara, Marta; Coulton, Les; Fisher, Simon E.; Croucher, Peter I.; Banham, Alison H.

2015-01-01

Mutations of the forkhead transcription factor FOXP2 gene have been implicated in inherited speech-and-language disorders, and specific Foxp2 expression patterns in neuronal populations and neuronal phenotypes arising from Foxp2 disruption have been described. However, molecular functions of FOXP2 are not completely understood. Here we report a requirement for FOXP2 in growth arrest of the osteosarcoma cell line 143B. We observed endogenous expression of this transcription factor both transiently in normally developing murine osteoblasts and constitutively in human SAOS-2 osteosarcoma cells blocked in early osteoblast development. Critically, we demonstrate that in 143B osteosarcoma cells with minimal endogenous expression, FOXP2 induced by growth arrest is required for up-regulation of p21WAF1/CIP1. Upon growth factor withdrawal, FOXP2 induction occurs rapidly and precedes p21WAF1/CIP1 activation. Additionally, FOXP2 expression could be induced by MAPK pathway inhibition in growth-arrested 143B cells, but not in traditional cell line models of osteoblast differentiation (MG-63, C2C12, MC3T3-E1). Our data are consistent with a model in which transient upregulation of Foxp2 in pre-osteoblast mesenchymal cells regulates a p21-dependent growth arrest checkpoint, which may have implications for normal mesenchymal and osteosarcoma biology. PMID:26034982

P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest

PubMed Central

Shamseddine, A A; Clarke, C J; Carroll, B; Airola, M V; Mohammed, S; Rella, A; Obeid, L M; Hannun, Y A

2015-01-01

Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest. PMID:26512957

P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest.

PubMed

Shamseddine, A A; Clarke, C J; Carroll, B; Airola, M V; Mohammed, S; Rella, A; Obeid, L M; Hannun, Y A

2015-10-29

Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest.

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

PubMed

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

2012-01-07

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

Existence, functional impairment, and lung repair potential of endothelial colony-forming cells in oxygen-induced arrested alveolar growth.

PubMed

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

2014-05-27

Bronchopulmonary dysplasia and emphysema are life-threatening diseases resulting from impaired alveolar development or alveolar destruction. Both conditions lack effective therapies. Angiogenic growth factors promote alveolar growth and contribute to alveolar maintenance. Endothelial colony-forming cells (ECFCs) represent a subset of circulating and resident endothelial cells capable of self-renewal and de novo vessel formation. We hypothesized that resident ECFCs exist in the developing lung, that they are impaired during arrested alveolar growth in experimental bronchopulmonary dysplasia, and that exogenous ECFCs restore disrupted alveolar growth. Human fetal and neonatal rat lungs contain ECFCs with robust proliferative potential, secondary colony formation on replating, and de novo blood vessel formation in vivo when transplanted into immunodeficient mice. In contrast, human fetal lung ECFCs exposed to hyperoxia in vitro and neonatal rat ECFCs isolated from hyperoxic alveolar growth-arrested rat lungs mimicking bronchopulmonary dysplasia proliferated less, showed decreased clonogenic capacity, and formed fewer capillary-like networks. Intrajugular administration of human cord blood-derived ECFCs after established arrested alveolar growth restored lung function, alveolar and lung vascular growth, and attenuated pulmonary hypertension. Lung ECFC colony- and capillary-like network-forming capabilities were also restored. Low ECFC engraftment and the protective effect of cell-free ECFC-derived conditioned media suggest a paracrine effect. Long-term (10 months) assessment of ECFC therapy showed no adverse effects with persistent improvement in lung structure, exercise capacity, and pulmonary hypertension. Impaired ECFC function may contribute to arrested alveolar growth. Cord blood-derived ECFC therapy may offer new therapeutic options for lung diseases characterized by alveolar damage. © 2014 American Heart Association, Inc.

FAST TRACK COMMUNICATION: A closer look at arrested spinodal decomposition in protein solutions

NASA Astrophysics Data System (ADS)

Gibaud, Thomas; Schurtenberger, Peter

2009-08-01

Concentrated aqueous solutions of the protein lysozyme undergo a liquid-solid transition upon a temperature quench into the unstable spinodal region below a characteristic arrest temperature of Tf = 15 °C. We use video microscopy and ultra-small angle light scattering in order to investigate the arrested structures as a function of initial concentration, quench temperature and rate of the temperature quench. We find that the solid-like samples show all the features of a bicontinuous network that is formed through an arrested spinodal decomposition process. We determine the correlation length ξ and demonstrate that ξ exhibits a temperature dependence that closely follows the critical scaling expected for density fluctuations during the early stages of spinodal decomposition. These findings are in agreement with an arrest scenario based on a state diagram where the arrest or gel line extends far into the unstable region below the spinodal line. Arrest then occurs when during the early stage of spinodal decomposition the volume fraction phi2 of the dense phase intersects the dynamical arrest threshold phi2,Glass, upon which phase separation gets pinned into a space-spanning gel network with a characteristic length ξ.

Yield of reversible colloidal gels during flow start-up: release from kinetic arrest.

PubMed

Johnson, Lilian C; Landrum, Benjamin J; Zia, Roseanna N

2018-06-05

Yield of colloidal gels during start-up of shear flow is characterized by an overshoot in shear stress that accompanies changes in network structure. Prior studies of yield of reversible colloidal gels undergoing strong flow model the overshoot as the point at which network rupture permits fluidization. However, yield under weak flow, which is of interest in many biological and industrial fluids shows no such disintegration. The mechanics of reversible gels are influenced by bond strength and durability, where ongoing rupture and re-formation impart aging that deepens kinetic arrest [Zia et al., J. Rheol., 2014, 58, 1121], suggesting that yield be viewed as release from kinetic arrest. To explore this idea, we study reversible colloidal gels during start-up of shear flow via dynamic simulation, connecting rheological yield to detailed measurements of structure, bond dynamics, and potential energy. We find that pre-yield stress grows temporally with the changing roles of microscopic transport processes: early time behavior is set by Brownian diffusion; later, advective displacements permit relative particle motion that stretches bonds and stores energy. Stress accumulates in stretched, oriented bonds until yield, which is a tipping point to energy release, and is passed with a fully intact network, where the loss of very few bonds enables relaxation of many, easing glassy arrest. This is immediately followed by a reversal to growth in potential energy during bulk plastic deformation and condensation into larger particle domains, supporting the view that yield is an activated release from kinetic arrest. The continued condensation of dense domains and shrinkage of network surfaces, along with a decrease in the potential energy, permit the gel to evolve toward more complete phase separation, supporting our view that yield of weakly sheared gels is a 'non-equilibrium phase transition'. Our findings may be particularly useful for industrial or other coatings, where weak, slow application via shear may lead to phase separation, inhibiting smooth distribution.

Epidemiology and Outcomes After In-Hospital Cardiac Arrest After Pediatric Cardiac Surgery

PubMed Central

Gupta, Punkaj; Jacobs, Jeffrey P.; Pasquali, Sara K.; Hill, Kevin D.; Gaynor, J. William; O’Brien, Sean M.; He, Max; Sheng, Shubin; Schexnayder, Stephen M.; Berg, Robert A.; Nadkarni, Vinay M.; Imamura, Michiaki; Jacobs, Marshall L.

2014-01-01

Background Multicenter data regarding cardiac arrest in children undergoing heart operations are limited. We describe epidemiology and outcomes associated with postoperative cardiac arrest in a large multiinstitutional cohort. Methods Patients younger than 18 years in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2007 through 2012) were included. Patient factors, operative characteristics, and outcomes were described for patients with and without postoperative cardiac arrest. Multivariable models were used to evaluate the association of center volume with cardiac arrest rate and mortality after cardiac arrest, adjusting for patient and procedural factors. Results Of 70,270 patients (97 centers), 1,843 (2.6%) had postoperative cardiac arrest. Younger age, lower weight, and presence of preoperative morbidities (all p < 0.0001) were associated with cardiac arrest. Arrest rate increased with procedural complexity across common benchmark operations, ranging from 0.7% (ventricular septal defect repair) to 12.7% (Norwood operation). Cardiac arrest was associated with significant mortality risk across procedures, ranging from 15.4% to 62.3% (all p < 0.0001). In multivariable analysis, arrest rate was not associated with center volume (odds ratio, 1.06; 95% confidence interval, 0.71 to 1.57 in low- versus high-volume centers). However, mortality after cardiac arrest was higher in low-volume centers (odds ratio, 2.00; 95% confidence interval, 1.52 to 2.63). This association was present for both high- and low-complexity operations. Conclusions Cardiac arrest carries a significant mortality risk across the stratum of procedural complexity. Although arrest rates are not associated with center volume, lower-volume centers have increased mortality after cardiac arrest. Further study of mechanisms to prevent cardiac arrest and to reduce mortality in those with an arrest is warranted. PMID:25443018

Utilization of palliative care services for cardiac arrest patients undergoing therapeutic hypothermia: A retrospective analysis.

PubMed

Zern, Emily K; Young, Michael N; Triana, Taylor; Xu, Meng; Holmes, Benjamin; Borges, Nyal; McPherson, John A; Karlekar, Mohana B

2017-03-01

Palliative care (PC) services are integral to the care of patients with advanced medical illnesses. Given the significant morbidity and mortality associated with cardiac arrest, we sought to measure the use and impact of PC in the care of patients treated with therapeutic hypothermia (TH). We conducted a retrospective study of 317 consecutive patients undergoing TH after cardiac arrest. We compared intensive care unit (ICU) characteristics and clinical outcomes of subjects who received PC consultation (n=125) to those who did not (n=192). The proportion of TH patients with PC consultations increased to greater than 60% by 2013, corresponding to our institution's expansion of PC services, development of a dedicated PC unit, and integration of this service into our published TH protocol. In the TH population, time to return of spontaneous circulation (ROSC) was associated with higher inpatient mortality (p<0.001) and placement of a PC consult (p=0.011). TH patients who received PC consultation had longer ICU stays (p=0.034), more ventilator days (p<0.001), and higher inpatient mortality (p<0.001). When these measures were analyzed cohort-wide comparing all TH patients pre- and post-2013, at which time the frequency of PC consultation had dramatically increased, there were no statistically significant differences in ICU care or outcomes. In our population of cardiac arrest patients undergoing TH, the utilization of PC services has increased over time, particularly for those patients with high morbidity and mortality. Future randomized studies may further delineate optimal patient selection for PC consultation to better facilitate goals of care discussions and timely medical decision-making. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

mTORC1 activation blocks BrafV600E-induced growth-arrest, but is insufficient for melanoma formation

PubMed Central

Damsky, William; Micevic, Goran; Meeth, Katrina; Muthusamy, Viswanathan; Curley, David P.; Santhankrishnan, Manjula; Erdelyi, Ildiko; Platt, James T.; Huang, Laura; Theodosakis, Nicholas; Zaidi, M. Raza; Tighe, Scott; Davies, Michael A.; Dankort, David; McMahon, Martin; Merlino, Glenn; Bardeesy, Nabeel; Bosenberg, Marcus

2014-01-01

SUMMARY BrafV600E induces benign, growth-arrested melanocytic nevus development, but also drives melanoma formation. Cdkn2a loss in BrafV600E melanocytes in mice results in rare progression to melanoma, but only after stable growth arrest as nevi. Immediate progression to melanoma is prevented by upregulation of miR-99/100 which downregulates mTOR and IGF1R signaling. mTORC1 activation through Stk11 (Lkb1) loss abrogates growth-arrest of BrafV600E melanocytic nevi, but is insufficient for complete progression to melanoma. Cdkn2a loss is associated with mTORC2 and Akt activation in human and murine melanocytic neoplasms. Simultaneous Cdkn2a and Lkb1 inactivation in BrafV600E melanocytes results in activation of both mTORC1 and mTORC2/Akt, inducing rapid melanoma formation in mice. In this model, activation of both mTORC1/2 is required for Braf-induced melanomagenesis. PMID:25584893

Identification of Fitness Determinants during Energy-Limited Growth Arrest in Pseudomonas aeruginosa.

PubMed

Basta, David W; Bergkessel, Megan; Newman, Dianne K

2017-11-28

Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen. Using transposon-insertion sequencing (Tn-seq), we identified fitness determinants in these two energy-limited states. Multiple genes encoding general functions like transcriptional regulation and energy generation were required for fitness during carbon or oxygen limitation, yet many specific genes, and thus specific activities, differed in their relevance between these states. For instance, the global regulator RpoS was required during both types of energy limitation, while other global regulators such as DksA and LasR were required only during carbon or oxygen limitation, respectively. Similarly, certain ribosomal and tRNA modifications were specifically required during oxygen limitation. We validated fitness defects during energy limitation using independently generated mutants of genes detected in our screen. Mutants in distinct functional categories exhibited different fitness dynamics: regulatory genes generally manifested a phenotype early, whereas genes involved in cell wall metabolism were required later. Together, these results provide a new window into how P. aeruginosa survives growth arrest. IMPORTANCE Growth-arrested bacteria are ubiquitous in nature and disease yet understudied at the molecular level. For example, growth-arrested cells constitute a major subpopulation of mature biofilms, serving as an antibiotic-tolerant reservoir in chronic infections. Identification of the genes required for survival of growth arrest (encompassing entry, maintenance, and exit) is an important first step toward understanding the physiology of bacteria in this state. Using Tn-seq, we identified and validated genes required for fitness of Pseudomonas aeruginosa when energy limited for organic carbon or oxygen, which represent two common causes of growth arrest for P. aeruginosa in diverse habitats. This unbiased, genome-wide survey is the first to reveal essential activities for a pathogen experiencing different types of energy limitation, finding both shared and divergent activities that are relevant at different survival stages. Future efforts can now be directed toward understanding how the biomolecules responsible for these activities contribute to fitness under these conditions. Copyright © 2017 Basta et al.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Kanayo; Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp; Tanaka, Satoshi

2014-01-03

Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDKmore » inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.« less

Reconsidering the process for bow-stave removal from juniper trees in the Great Basin

Treesearch

Constance I. Millar; Kevin T. Smith

2017-01-01

We question the growth arrestment hypothesis for bow stave removal used by indigenous people in the western Great Basin. Using modern understanding of tree growth and wound response, we suggest that growth would not be arrested by one or two transverse notches along a juniper stem. Rather these would trigger compartmentalization, which limits cambial death to within 10...

Sec13 safeguards the integrity of the endoplasmic reticulum and organogenesis of the digestive system in zebrafish.

PubMed

Niu, Xubo; Gao, Chuan; Jan Lo, Li; Luo, Yue; Meng, Chunmei; Hong, Jian; Hong, Wanjin; Peng, Jinrong

2012-07-15

The Sec13-Sec31 heterotetramer serves as the outer coat in the COPII complex, which mediates protein trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus. Although it has been studied in depth in yeast and cultured cells, the role of COPII in organogenesis in a multicellular organism has not. We report here that a zebrafish sec13(sq198) mutant, which exhibits a phenotype of hypoplastic digestive organs, has a mutation in the sec13 gene. The mutant gene encodes a carboxyl-terminus-truncated Sec13 that loses its affinity to Sec31a, which leads to disintegration of the ER structure in various differentiated cells in sec13(sq198), including chondrocytes, intestinal epithelial cells and hepatocytes. Disruption of the ER structure activates an unfolded protein response that eventually causes the cells to undergo cell-cycle arrest and cell apoptosis, which arrest the growth of developing digestive organs in the mutant. Our data provide the first direct genetic evidence that COPII function is essential for the organogenesis of the digestive system. Copyright © 2012 Elsevier Inc. All rights reserved.

Live-cell imaging visualizes frequent mitotic skipping during senescence-like growth arrest in mammary carcinoma cells exposed to ionizing radiation.

PubMed

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

2012-06-01

Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO(2)-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ß-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation. Copyright © 2012 Elsevier Inc. All rights reserved.

Translational arrest due to cytoplasmic redox stress delays adaptation to growth on methanol and heterologous protein expression in a typical fed-batch culture of Pichia pastoris.

PubMed

Edwards-Jones, Bryn; Aw, Rochelle; Barton, Geraint R; Tredwell, Gregory D; Bundy, Jacob G; Leak, David J

2015-01-01

We have followed a typical fed-batch induction regime for heterologous protein production under the control of the AOX1 promoter using both microarray and metabolomic analysis. The genetic constructs involved 1 and 3 copies of the TRY1 gene, encoding human trypsinogen. In small-scale laboratory cultures, expression of the 3 copy-number construct induced the unfolded protein response (UPR) sufficiently that titres of extracellular trypsinogen were lower in the 3-copy construct than with the 1-copy construct. In the fed-batch-culture, a similar pattern was observed, with higher expression from the 1-copy construct, but in this case there was no significant induction of UPR with the 3-copy strain. Analysis of the microarray and metabolomic information indicates that the 3-copy strain was undergoing cytoplasmic redox stress at the point of induction with methanol. In this Crabtree-negative yeast, this redox stress appeared to delay the adaptation to growth on methanol and supressed heterologous protein production, probably due to a block in translation. Although redox imbalance as a result of artificially imposed hypoxia has previously been described, this is the first time that it has been characterised as a result of a transient metabolic imbalance and shown to involve a stress response which can lead to translational arrest. Without detailed analysis of the underlying processes it could easily have been mis-interpreted as secretion stress, transmitted through the UPR.

New white matter brain injury after infant heart surgery is associated with diagnostic group and the use of circulatory arrest.

PubMed

Beca, John; Gunn, Julia K; Coleman, Lee; Hope, Ayton; Reed, Peter W; Hunt, Rodney W; Finucane, Kirsten; Brizard, Christian; Dance, Brieana; Shekerdemian, Lara S

2013-03-05

Abnormalities on magnetic resonance imaging scans are common both before and after surgery for congenital heart disease in early infancy. The aim of this study was to prospectively investigate the nature, timing, and consequences of brain injury on magnetic resonance imaging in a cohort of young infants undergoing surgery for congenital heart disease both with and without cardiopulmonary bypass. A total of 153 infants undergoing surgery for congenital heart disease at <8 weeks of age underwent serial magnetic resonance imaging scans before and after surgery and at 3 months of age, as well as neurodevelopmental assessment at 2 years of age. White matter injury (WMI) was the commonest type of injury both before and after surgery. It occurred in 20% of infants before surgery and was associated with a less mature brain. New WMI after surgery was present in 44% of infants and at similar rates after surgery with or without cardiopulmonary bypass. The most important association was diagnostic group (P<0.001). In infants having arch reconstruction, the use and duration of circulatory arrest were significantly associated with new WMI. New WMI was also associated with the duration of cardiopulmonary bypass, postoperative lactate level, brain maturity, and WMI before surgery. Brain immaturity but not brain injury was associated with impaired neurodevelopment at 2 years of age. New WMI is common after surgery for congenital heart disease and occurs at the same rate in infants undergoing surgery with and without cardiopulmonary bypass. New WMI is associated with diagnostic group and, in infants undergoing arch surgery, the use of circulatory arrest.

Seasonal bone growth and physiology in endotherms shed light on dinosaur physiology.

PubMed

Köhler, Meike; Marín-Moratalla, Nekane; Jordana, Xavier; Aanes, Ronny

2012-07-19

Cyclical growth leaves marks in bone tissue that are in the forefront of discussions about physiologies of extinct vertebrates. Ectotherms show pronounced annual cycles of growth arrest that correlate with a decrease in body temperature and metabolic rate; endotherms are assumed to grow continuously until they attain maturity because of their constant high body temperature and sustained metabolic rate. This apparent dichotomy has driven the argument that zonal bone denotes ectotherm-like physiologies, thus fuelling the controversy on dinosaur thermophysiology and the evolution of endothermy in birds and mammal-like reptiles. Here we show, from a comprehensive global study of wild ruminants from tropical to polar environments, that cyclical growth is a universal trait of homoeothermic endotherms. Growth is arrested during the unfavourable season concurrently with decreases in body temperature, metabolic rate and bone-growth-mediating plasma insulin-like growth factor-1 levels, forming part of a plesiomorphic thermometabolic strategy for energy conservation. Conversely, bouts of intense tissue growth coincide with peak metabolic rates and correlated hormonal changes at the beginning of the favourable season, indicating an increased efficiency in acquiring and using seasonal resources. Our study supplies the strongest evidence so far that homeothermic endotherms arrest growth seasonally, which precludes the use of lines of arrested growth as an argument in support of ectothermy. However, high growth rates are a distinctive trait of mammals, suggesting the capacity for endogenous heat generation. The ruminant annual cycle provides an extant model on which to base inferences regarding the thermophysiology of dinosaurs and other extinct taxa.

The Host Range of Gammaretroviruses and Gammaretroviral Vectors Includes Post-Mitotic Neural Cells

PubMed Central

Liu, Xiu-Huai; Xu, Wenqin; Russ, Jill; Eiden, Lee E.; Eiden, Maribeth V.

2011-01-01

Background Gammaretroviruses and gammaretroviral vectors, in contrast to lentiviruses and lentiviral vectors, are reported to be restricted in their ability to infect growth-arrested cells. The block to this restriction has never been clearly defined. The original assessment of the inability of gammaretroviruses and gammaretroviral vectors to infect growth-arrested cells was carried out using established cell lines that had been growth-arrested by chemical means, and has been generalized to neurons, which are post-mitotic. We re-examined the capability of gammaretroviruses and their derived vectors to efficiently infect terminally differentiated neuroendocrine cells and primary cortical neurons, a target of both experimental and therapeutic interest. Methodology/Principal Findings Using GFP expression as a marker for infection, we determined that both growth-arrested (NGF-differentiated) rat pheochromocytoma cells (PC12 cells) and primary rat cortical neurons could be efficiently transduced, and maintained long-term protein expression, after exposure to murine leukemia virus (MLV) and MLV-based retroviral vectors. Terminally differentiated PC12 cells transduced with a gammaretroviral vector encoding the anti-apoptotic protein Bcl-xL were protected from cell death induced by withdrawal of nerve growth factor (NGF), demonstrating gammaretroviral vector-mediated delivery and expression of genes at levels sufficient for therapeutic effect in non-dividing cells. Post-mitotic rat cortical neurons were also shown to be susceptible to transduction by murine replication-competent gammaretroviruses and gammaretroviral vectors. Conclusions/Significance These findings suggest that the host range of gammaretroviruses includes post-mitotic and other growth-arrested cells in mammals, and have implications for re-direction of gammaretroviral gene therapy to neurological disease. PMID:21464894

Chromosomal Aneuploidies and Early Embryonic Developmental Arrest.

PubMed

Maurer, Maria; Ebner, Thomas; Puchner, Manuela; Mayer, Richard Bernhard; Shebl, Omar; Oppelt, Peter; Duba, Hans-Christoph

2015-01-01

Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF) technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH) with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting.

Signaling molecules involved in the transition of growth to development of Dictyostelium discoideum.

PubMed

Mir, Hina A; Rajawat, Jyotika; Pradhan, Shalmali; Begum, Rasheedunnisa

2007-03-01

The social amoeba Dictyostelium discoideum, a powerful paradigm provides clear insights into the regulation of growth and development. In addition to possessing complex individual cellular functions like a unicellular eukaryote, D. discoideum cells face the challenge of multicellular development. D. discoideum undergoes a relatively simple differentiation process mainly by cAMP mediated pathway. Despite this relative simplicity, the regulatory signaling pathways are as complex as those seen in metazoan development. However, the introduction of restriction-enzyme-mediated integration (REMI) technique to produce developmental gene knockouts has provided novel insights into the discovery of signaling molecules and their role in D. discoideum development. Cell cycle phase is an important aspect for differentiation of D. discoideum, as cells must reach a specific stage to enter into developmental phase and specific cell cycle regulators are involved in arresting growth phase genes and inducing the developmental genes. In this review, we present an overview of the signaling molecules involved in the regulation of growth to differentiation transition (GDT), molecular mechanism of early developmental events leading to generation of cAMP signal and components of cAMP relay system that operate in this paradigm.

p53-dependent p21-mediated growth arrest pre-empts and protects HCT116 cells from PUMA-mediated apoptosis induced by EGCG

PubMed Central

Thakur, Vijay S; Amin, A.R.M. Ruhul; Paul, Rajib K; Gupta, Kalpana; Hastak, Kedar; Agarwal, Mukesh K; Jackson, Mark W; Wald, David N; Mukhtar, Hasan; Agarwal, Munna L

2010-01-01

The tumor suppressor protein p53 plays a key role in regulation of negative cellular growth in response to EGCG. To further explore the role of p53 signaling and elucidate the molecular mechanism, we employed colon cancer HCT116 cell line and its derivatives in which a specific transcriptional target of p53 is knocked down by homologous recombination. Cells expressing p53 and p21 accumulate in G1 upon treatment with EGCG. In contrast, same cells lacking p21 traverse through the cell cycle and eventually undergo apoptosis as revealed by TUNEL staining. Treatment with EGCG leads to induction of p53, p21 and PUMA in p21 wild-type, and p53 and PUMA in p21−/− cells. Ablation of p53 by RNAi protects p21−/− cells, thus indicating a p53-dependent apoptosis by EGCG. Furthermore, analysis of cells lacking PUMA or Bax with or without p21 but with p53 reveals that all the cells expressing p53 and p21 survived after EGCG treatment. More interestingly, cells lacking both PUMA and p21 survived ECGC treatment whereas those lacking p21 and Bax did not. Taken together, our results present a novel concept wherein p21-dependent growth arrest pre-empts and protects cells from otherwise, in its absence, apoptosis which is mediated by activation of pro-apoptotic protein PUMA. Furthermore, we find that p53-dependent activation of PUMA in response to EGCG directly leads to apoptosis with out requiring Bax as is the case in response to agents that induce DNA damage. p21, thus can be used as a molecular switch for therapeutic intervention of colon cancer. PMID:20444544

Effects of nutrient deprivation and differentiation on the expression of growth-arrest genes (gas and gadd) in F9 embryonal carcinoma cells.

PubMed Central

Fleming, J V; Hay, S M; Harries, D N; Rees, W D

1998-01-01

The growth-arrest genes (gas and gadd) are widely expressed during mammalian embryogenesis and may be useful as markers of nutritional stress in the embryo. F9 embryonal carcinoma cells have been used to characterize the effect of serum or amino acid deficiency on growth-arrest gene expression in a differentiating embryonic cell. The differentiation markers, homeobox B2 (HoxB2), collagen type IV and laminin B2, were not induced by growth arrest. Treatment with all-trans retinoic acid (RA) produced a dose-dependent increase in alkaline phosphatase activity, which was unchanged in lysine-deficient medium and reduced in low-serum medium. Low-serum medium also reduced HoxB2 expression. There was a transient 2-6-fold increase in mRNAs for C/EBP-beta, gadd153/CHOP-10 and gas5 genes 24 h after transfer to amino-acid-deficient media. The mRNAs for the gas2 and gas6 genes began to rise slowly by 5-10-fold after a delay of approx. 24 h. The transient increases did not occur in low-serum medium where there was a much smaller and slower increase. Differentiation caused 1-2-fold increases in gas2, gas3 and gas6 mRNA levels. The transient overexpression of gas5, gadd153/CHOP-10 and CCAAT-enhancer-binding protein-beta, and the later expression of gas6 mRNAs in response to amino acid deficiency, were not affected by differentiation. RA treatment increased the expression of gas3 and caused gas2 to be transiently overexpressed in amino-acid-deficient medium. Differentiation in serum-deficient medium did not significantly alter the levels of the growth-arrest gene mRNAs. These results show that in F9 cells the growth-arrest genes are expressed sequentially as a result of nutrient stress. PMID:9461558

Effects of nutrient deprivation and differentiation on the expression of growth-arrest genes (gas and gadd) in F9 embryonal carcinoma cells.

PubMed

Fleming, J V; Hay, S M; Harries, D N; Rees, W D

1998-02-15

The growth-arrest genes (gas and gadd) are widely expressed during mammalian embryogenesis and may be useful as markers of nutritional stress in the embryo. F9 embryonal carcinoma cells have been used to characterize the effect of serum or amino acid deficiency on growth-arrest gene expression in a differentiating embryonic cell. The differentiation markers, homeobox B2 (HoxB2), collagen type IV and laminin B2, were not induced by growth arrest. Treatment with all-trans retinoic acid (RA) produced a dose-dependent increase in alkaline phosphatase activity, which was unchanged in lysine-deficient medium and reduced in low-serum medium. Low-serum medium also reduced HoxB2 expression. There was a transient 2-6-fold increase in mRNAs for C/EBP-beta, gadd153/CHOP-10 and gas5 genes 24 h after transfer to amino-acid-deficient media. The mRNAs for the gas2 and gas6 genes began to rise slowly by 5-10-fold after a delay of approx. 24 h. The transient increases did not occur in low-serum medium where there was a much smaller and slower increase. Differentiation caused 1-2-fold increases in gas2, gas3 and gas6 mRNA levels. The transient overexpression of gas5, gadd153/CHOP-10 and CCAAT-enhancer-binding protein-beta, and the later expression of gas6 mRNAs in response to amino acid deficiency, were not affected by differentiation. RA treatment increased the expression of gas3 and caused gas2 to be transiently overexpressed in amino-acid-deficient medium. Differentiation in serum-deficient medium did not significantly alter the levels of the growth-arrest gene mRNAs. These results show that in F9 cells the growth-arrest genes are expressed sequentially as a result of nutrient stress.

Phase Coexistence and Kinetic Arrest in the Magnetostructural Transition of the Ordered Alloy FeRh

DOE PAGES

Keavney, David J.; Choi, Yongseong; Holt, Martin V.; ...

2018-01-29

In materials where two or more ordering degrees of freedom are closely matched in their free energies, coupling between them, or multiferroic behavior can occur. These phenomena can produce a very rich phase behavior, as well as emergent phases that offer useful properties and opportunities to reveal novel phenomena in phase transitions. The ordered alloy FeRh undergoes an antiferromagnetic to ferromagnetic phase transition at ~375 K, which illustrates the interplay between structural and magnetic order mediated by a delicate energy balance between two configurations. We have examined this transition using a combination of high-resolution x-ray structural and magnetic imaging andmore » comprehensive x-ray magnetic circular dichroism spectroscopy. We find that the transition proceeds via a defect-driven domain nucleation and growth mechanism, with significant return point memory in both the structural and magnetic domain configurations. In conclusion, the domains show evidence of inhibited growth after nucleation, resulting in a quasi- 2nd order temperature behavior.« less

Percutenous Catheter Ablation of the Accessory Pathway in a Patient with Wolff-Parkinson-White Syndrome Associated with Familial Atrial Fibrillation

PubMed Central

Cay, Serkan; Topaloglu, Serkan; Aras, Dursun

2008-01-01

Percutenous catheter ablation of the accessory pathway in Wolff-Parkinson-White syndrome is a highly successful mode of therapy. Sudden cardiac arrest survivors associated with WPW syndrome should undergo radiofrequency catheter ablation. WPW syndrome associated with familial atrial fibrillation is a very rare condition. Herein, we describe a case who presented with sudden cardiac arrest secondary to WPW syndrome and familial atrial fibrillation and treated via radiofrequency catheter ablation. PMID:18379660

Rationale, development and implementation of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest.

PubMed

Morrison, Laurie J; Nichol, Graham; Rea, Thomas D; Christenson, Jim; Callaway, Clifton W; Stephens, Shannon; Pirrallo, Ronald G; Atkins, Dianne L; Davis, Daniel P; Idris, Ahamed H; Newgard, Craig

2008-08-01

To describe the development, design and consequent scientific implications of the Resuscitation Outcomes Consortium (ROC) population-based registry; ROC Epistry-Cardiac Arrest. The ROC Epistry--Cardiac Arrest is designed as a prospective population-based registry of all Emergency Medical Services (EMSs)-attended 9-1-1 calls for patients with out-of-hospital cardiac arrest occurring in the geographical area described by the eight US and three Canadian regions. The dataset was derived by an North American interdisciplinary steering committee. Enrolled cases include individuals of all ages who experience cardiac arrest outside the hospital, with evaluation by organized EMS personnel and: (a) attempts at external defibrillation (by lay responders or emergency personnel), or chest compressions by organized EMS personnel; (b) were pulseless but did not receive attempts to defibrillate or CPR by EMS personnel. Selected data items are categorized as mandatory or optional and undergo revisions approximately every 12 months. Where possible all definitions are referenced to existing literature. Where a common definition did not exist one was developed. Optional items include standardized CPR process data elements. It is anticipated the ROC Epistry--Cardiac Arrest will enroll between approximately 9000 and 13,500 treated all rhythm arrests and 4000 and 5000 ventricular fibrillation arrests annually and approximately 8000 EMS-attended but untreated arrests. We describe the rationale, development, design and future implications of the ROC Epistry--Cardiac Arrest. This paper will serve as the reference for subsequent ROC manuscripts and for the common data elements captured in both ROC Epistry--Cardiac Arrest and the ROC trials.

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

An evaluation of the choice of feeder cell growth arrest for the production of cultured epidermis.

PubMed

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

2015-12-01

Growth arrested 3T3 cells have been used as feeder cells in human epidermal keratinocyte cultures to produce cultured epidermal autografts for the treatment of burns. The feeder cells were ideally growth-arrested by gamma-irradiation. Alternatively, growth arrest by mitomycin C treatment is a cost effective option. We compared the functional efficacy of these two approaches in keratinocyte cultures by colony forming efficiency, the net growth area of colonies, BrdU labeling and histological features of cultured epidermal sheets. The growth area estimation involved a semi-automated digital technique using the Adobe Photoshop and comprised of isolation and enumeration of red pixels in Rhodamine B-stained keratinocyte colonies. A further refinement of the technique led to the identification of critical steps to increasing the degree of accuracy and enabling its application as an extension of colony formation assay. The results on feeder cell functionality revealed that the gamma irradiated feeders influenced significantly higher colony forming efficiency and larger growth area than the mitomycin C treated feeders. The BrdU labeling study indicated significant stimulation of the overall keratinocyte proliferation by the gamma irradiated feeders. The cultured epidermal sheets produced by gamma feeders were relatively thicker than those produced by mitomycin C feeders. We discussed the clinical utility of mitomycin C feeders from the viewpoint of cost-effective burn care in developing countries. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Chromosomal Aneuploidies and Early Embryonic Developmental Arrest

PubMed Central

Maurer, Maria; Ebner, Thomas; Puchner, Manuela; Mayer, Richard Bernhard; Shebl, Omar; Oppelt, Peter; Duba, Hans-Christoph

2015-01-01

Background Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF) technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. Materials and Methods This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH) with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Results Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Conclusion Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting. PMID:26644858

Hypoxia-inducible factors promote alveolar development and regeneration.

PubMed

Vadivel, Arul; Alphonse, Rajesh S; Etches, Nicholas; van Haaften, Timothy; Collins, Jennifer J P; O'Reilly, Megan; Eaton, Farah; Thébaud, Bernard

2014-01-01

Understanding how alveoli and the underlying capillary network develop and how these mechanisms are disrupted in disease states is critical for developing effective therapies for lung regeneration. Recent evidence suggests that lung angiogenesis promotes lung development and repair. Vascular endothelial growth factor (VEGF) preserves lung angiogenesis and alveolarization in experimental O2-induced arrested alveolar growth in newborn rats, but combined VEGF+angiopoietin 1 treatment is necessary to correct VEGF-induced vessel leakiness. Hypoxia-inducible factors (HIFs) are transcription factors that activate multiple O2-sensitive genes, including those encoding for angiogenic growth factors, but their role during postnatal lung growth is incompletely understood. By inducing the expression of a range of angiogenic factors in a coordinated fashion, HIF may orchestrate efficient and safe angiogenesis superior to VEGF. We hypothesized that HIF inhibition impairs alveolarization and that HIF activation regenerates irreversible O2-induced arrested alveolar growth. HIF inhibition by intratracheal dominant-negative adenovirus (dnHIF-1α)-mediated gene transfer or chetomin decreased lung HIF-1α, HIF-2α, and VEGF expression and led to air space enlargement and arrested lung vascular growth. In experimental O2-induced arrested alveolar growth in newborn rats, the characteristic features of air space enlargement and loss of lung capillaries were associated with decreased lung HIF-1α and HIF-2α expression. Intratracheal administration of Ad.HIF-1α restored HIF-1α, endothelial nitric oxide synthase, VEGF, VEGFR2, and Tie2 expression and preserved and rescued alveolar growth and lung capillary formation in this model. HIFs promote normal alveolar development and may be useful targets for alveolar regeneration.

Premature Growth Plate Closure in a Ballet Dancer en Pointe.

PubMed

Shah, Selina

2017-09-01

A 13-year-old ballet dancer who had been dancing en pointe (on the tips of the toes) since 10 years presented to the clinic with a shortened right second toe. She had no previous history of pain or trauma. She was diagnosed with premature growth arrest of the second metatarsal head physes resulting in a shortened metatarsal. This is the first reported case of premature growth arrest in a ballet dancer as a result of dancing en pointe.

Functional analysis of a biosynthetic cluster essential for production of 4-formylaminooxyvinylglycine, a germination-arrest factor from Pseudomonas fluorescens WH6

USDA-ARS?s Scientific Manuscript database

Rhizosphere-associated Pseudomonas fluorescens WH6 produces the germination-arrest factor, 4-formylaminooxyvinylglycine (FVG). FVG has previously been shown to both arrest the germination of weedy grasses and to inhibit the growth of the bacterial plant pathogen Erwinia amylovora. Very little is kno...

Juvenile Arrests 1996. Juvenile Justice Bulletin.

ERIC Educational Resources Information Center

Snyder, Howard N.

In 1996, law enforcement agencies in the United States made an estimated 2.9 million arrests of persons under the age of 18. According to Federal Bureau of Investigation (FBI) figures, juveniles accounted for 19% of all arrests and 19% of all violent crime in 1996. The substantial growth in juvenile crime that began in the late 1980s peaked in…

Mechanisms underlying the growth inhibitory effects of the cyclo-oxygenase-2 inhibitor celecoxib in human breast cancer cells.

PubMed

Basu, Gargi D; Pathangey, Latha B; Tinder, Teresa L; Gendler, Sandra J; Mukherjee, Pinku

2005-01-01

Inhibitors of cyclo-oxygenase (COX)-2 are being extensively studied as anticancer agents. In the present study we evaluated the mechanisms by which a highly selective COX-2 inhibitor, celecoxib, affects tumor growth of two differentially invasive human breast cancer cell lines. MDA-MB-231 (highly invasive) and MDA-MB-468 (moderately invasive) cell lines were treated with varying concentrations of celecoxib in vitro, and the effects of this agent on cell growth and angiogenesis were monitored by evaluating cell proliferation, apoptosis, cell cycle arrest, and vasculogenic mimicry. The in vitro results of MDA-MB-231 cell line were further confirmed in vivo in a mouse xenograft model. The highly invasive MDA-MB-231 cells express higher levels of COX-2 than do the less invasive MDA-MB-468 cells. Celecoxib treatment inhibited COX-2 activity, indicated by prostaglandin E2 secretion, and caused significant growth arrest in both breast cancer cell lines. In the highly invasive MDA-MB-231 cells, the mechanism of celecoxib-induced growth arrest was by induction of apoptosis, associated with reduced activation of protein kinase B/Akt, and subsequent activation of caspases 3 and 7. In the less invasive MDA-MB-468 cells, growth arrest was a consequence of cell cycle arrest at the G0/G1 checkpoint. Celecoxib-induced growth inhibition was reversed by addition of exogenous prostaglandin E2 in MDA-MB-468 cells but not in MDA-MB-231 cells. Furthermore, MDA-MB-468 cells formed significantly fewer extracellular matrix associated microvascular channels in vitro than did the high COX-2 expressing MDA-MB-231 cells. Celecoxib treatment not only inhibited cell growth and vascular channel formation but also reduced vascular endothelial growth factor levels. The in vitro findings corroborated in vivo data from a mouse xenograft model in which daily administration of celecoxib significantly reduced tumor growth of MDA-MB-231 cells, which was associated with reduced vascularization and increased necrosis in the tumor mass. The disparate molecular mechanisms of celecoxib-induced growth inhibition in human breast cancer cells depends upon the level of COX-2 expression and the invasive potential of the cell lines examined. Data suggest a role for COX-2 not only in the growth of cancer cells but also in activating the angiogenic pathway through regulating levels of vascular endothelial growth factor.

Modeling the Arrest of Tissue Growth in Epithelia

NASA Astrophysics Data System (ADS)

Golden, Alexander; Lubensky, David

The mechanisms of control and eventual arrest of growth of tissues is an area that has received considerable attention, both experimentally and in the development of quantitative models. In particular, the Drosophila wing disc epithelium appears to robustly arrive at a unique final size. One mechanism that has the potential to play a role in the eventual cessation of growth is mechanical feedback from stresses induced by nonuniform growth. There is experimental support for an effect on the tissue growth rate by such mechanical stresses, and a number of numerical or cell-based models have been proposed that show that the arrest of growth can be achieved by mechanical feedback. We introduce an analytic framework that allows us to understand different coarse-grained feedback mechanisms on the same terms. We use the framework to distinguish between families of models that do not have a unique final size and those that do and give rough estimates for how much variability in the eventual organ size can be expected in models that do not have a unique final size. NSF Grant DMR-1056456.

Sulforaphane induces reactive oxygen species-mediated mitotic arrest and subsequent apoptosis in human bladder cancer 5637 cells.

PubMed

Park, Hyun Soo; Han, Min Ho; Kim, Gi-Young; Moon, Sung-Kwon; Kim, Wun-Jae; Hwang, Hye Jin; Park, Kun Young; Choi, Yung Hyun

2014-02-01

The present study was undertaken to determine whether sulforaphane-derived reactive oxygen species (ROS) might cause growth arrest and apoptosis in human bladder cancer 5637 cells. Our results show that the reduced viability of 5637 cells by sulforaphane is due to mitotic arrest, but not the G2 phase. The sulforaphane-induced mitotic arrest correlated with an induction of cyclin B1 and phosphorylation of Cdk1, as well as a concomitant increased complex between cyclin B1 and Cdk1. Sulforaphane-induced apoptosis was associated with the activation of caspase-8 and -9, the initiators caspases of the extrinsic and intrinsic apoptotic pathways, respectively, and activation of effector caspase-3 and cleavage of poly (ADP-ribose) polymerase. However, blockage of caspase activation inhibited apoptosis and abrogated growth inhibition in sulforaphane-treated 5637 cells. This study further investigated the roles of ROS with respect to mitotic arrest and the apoptotic effect of sulforaphane, and the maximum level of ROS accumulation was observed 3h after sulforaphane treatment. However, a ROS scavenger, N-acetyl-L-cysteine, notably attenuated sulforaphane-mediated apoptosis as well as mitotic arrest. Overall, these results suggest that sulforaphane induces mitotic arrest and apoptosis of 5637 cells via a ROS-dependent pathway. Copyright © 2013 Elsevier Ltd. All rights reserved.

MYC activation is a hallmark of cancer initiation and maintenance.

PubMed

Gabay, Meital; Li, Yulin; Felsher, Dean W

2014-06-02

The MYC proto-oncogene has been implicated in the pathogenesis of most types of human tumors. MYC activation alone in many normal cells is restrained from causing tumorigenesis through multiple genetic and epigenetically controlled checkpoint mechanisms, including proliferative arrest, apoptosis, and cellular senescence. When pathologically activated in a permissive epigenetic and/or genetic context, MYC bypasses these mechanisms, enforcing many of the "hallmark" features of cancer, including relentless tumor growth associated with DNA replication and transcription, cellular proliferation and growth, protein synthesis, and altered cellular metabolism. MYC mandates tumor cell fate, by inducing stemness and blocking cellular senescence and differentiation. Additionally, MYC orchestrates changes in the tumor microenvironment, including the activation of angiogenesis and suppression of the host immune response. Provocatively, brief or even partial suppression of MYC back to its physiological levels of activation can result in the restoration of intrinsic checkpoint mechanisms, resulting in acute and sustained tumor regression, associated with tumor cells undergoing proliferative arrest, differentiation, senescence, and apoptosis, as well as remodeling of the tumor microenvironment, recruitment of an immune response, and shutdown of angiogenesis. Hence, tumors appear to be "addicted" to MYC because of both tumor cell-intrinsic, cell-autonomous and host-dependent, immune cell-dependent mechanisms. Both the trajectory and persistence of many human cancers require sustained MYC activation. Multiscale mathematical modeling may be useful to predict when tumors will be addicted to MYC. MYC is a hallmark molecular feature of both the initiation and maintenance of tumorigenesis. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Translational Arrest Due to Cytoplasmic Redox Stress Delays Adaptation to Growth on Methanol and Heterologous Protein Expression in a Typical Fed-Batch Culture of Pichia pastoris

PubMed Central

Edwards-Jones, Bryn; Aw, Rochelle; Barton, Geraint R.; Tredwell, Gregory D.; Bundy, Jacob G.; Leak, David J.

2015-01-01

Results We have followed a typical fed-batch induction regime for heterologous protein production under the control of the AOX1 promoter using both microarray and metabolomic analysis. The genetic constructs involved 1 and 3 copies of the TRY1 gene, encoding human trypsinogen. In small-scale laboratory cultures, expression of the 3 copy-number construct induced the unfolded protein response (UPR) sufficiently that titres of extracellular trypsinogen were lower in the 3-copy construct than with the 1-copy construct. In the fed-batch-culture, a similar pattern was observed, with higher expression from the 1-copy construct, but in this case there was no significant induction of UPR with the 3-copy strain. Analysis of the microarray and metabolomic information indicates that the 3-copy strain was undergoing cytoplasmic redox stress at the point of induction with methanol. In this Crabtree-negative yeast, this redox stress appeared to delay the adaptation to growth on methanol and supressed heterologous protein production, probably due to a block in translation. Conclusion Although redox imbalance as a result of artificially imposed hypoxia has previously been described, this is the first time that it has been characterised as a result of a transient metabolic imbalance and shown to involve a stress response which can lead to translational arrest. Without detailed analysis of the underlying processes it could easily have been mis-interpreted as secretion stress, transmitted through the UPR. PMID:25785713

DYZ1 copy number variation, Y chromosome polymorphism and early recurrent spontaneous abortion/early embryo growth arrest.

PubMed

Yan, Junhao; Fan, Lingling; Zhao, Yueran; You, Li; Wang, Laicheng; Zhao, Han; Li, Yuan; Chen, Zi-Jiang

2011-12-01

To find the association between recurrent spontaneous abortion (RSA)/early embryo growth arrest and Y chromosome polymorphism. Peripheral blood samples of the male patients of big Y chromosome, small Y chromosome and other male patients whose partners suffered from unexplained RSA/early embryo growth arrest were collected. PCR and real-time fluorescent quantitative PCR were used to test the deletion and the copy number variation of DYZ1 region in Y chromosome of the patients. A total of 79 big Y chromosome patients (48 of whose partners suffered from RSA or early embryo growth arrest), 7 small Y chromosome patients, 106 other male patients whose partners had suffered from unexplained RSA or early embryo growth arrest, and 100 normal male controls were enrolled. There was no fraction deletion of DYZ1 detected both in big Y patients and in normal men. Of RSA patients, 1 case showed deletion of 266bp from the gene locus 25-290bp, and 2 cases showed deletion of 773bp from 1347 to 2119bp. Of only 7 small Y chromosome patients, 2 cases showed deletion of 266bp from 25 to 290bp, and 4 cases showed deletion of 773bp from 1347 to 2119bp and 275bp from 3128 to 3420bp. The mean of DYZ1 copies was 3900 in normal control men; the mean in big Y patients was 5571, in RSA patients was 2655, and in small Y patients was 1059. All of the others were significantly different (P<0.01) compared with normal control men, which meant that DYZ1 copy number in normal control men was less than that of big Y chromosome patients, and was more than that of unexplained early RSA patients and small Y patients. The integrity and copy number variation of DYZ1 are closely related to the Y chromosome length under microscope. The cause of RSA/early embryo growth arrest in some couples may be the increase (big Y patients) or decrease of DYZ1 copy number in the husbands' Y chromosome. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A combinatorial strategy of alternative promoter use during differentiation of a heterocystous cyanobacterium.

PubMed

Muro-Pastor, Alicia M; Brenes-Álvarez, Manuel; Vioque, Agustín

2017-08-01

Heterocystous cyanobacteria such as Nostoc sp. are filamentous photosynthetic organisms that, in response to nitrogen deficiency, undergo a differentiation process transforming certain, semi-regularly spaced cells into heterocysts, devoted to nitrogen fixation. During transition to a nitrogen-fixing regime, growth of most vegetative cells in the filament is temporarily arrested due to nutritional deprivation, but developing heterocysts require intense transcriptional activity. Therefore, the coexistence of arrested vegetative cells and actively developing prospective heterocysts relies on the simultaneous operation of somewhat opposite transcriptional programs. We have identified genes with multiple nitrogen-responsive transcriptional starts appearing in seemingly paradoxical combinations. For instance, sigA, encoding the RNA polymerase housekeeping sigma factor, is transcribed from one major nitrogen stress-repressed promoter and from a second, nitrogen stress-induced promoter. Here, we show that both promoters are expressed with complementary temporal dynamics. Using a gfp reporter we also show that transcription from the inducible promoter takes place exclusively in differentiating heterocysts and is already detected before any morphological or fluorescence signature of differentiation is observed. Tandem promoters with opposite dynamics could operate a compensatory mechanism in which repression of transcription from the major promoter operative in vegetative cells is offset by transcription from a new promoter only in developing heterocyst. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

GADD45α sensitizes cervical cancer cells to radiotherapy via increasing cytoplasmic APE1 level.

PubMed

Li, Qing; Wei, Xi; Zhou, Zhi-Wei; Wang, Shu-Nan; Jin, Hua; Chen, Kui-Jun; Luo, Jia; Westover, Kenneth D; Wang, Jian-Min; Wang, Dong; Xu, Cheng-Xiong; Shan, Jin-Lu

2018-05-09

Radioresistance remains a major clinical challenge in cervical cancer therapy. However, the mechanism for the development of radioresistance in cervical cancer is unclear. Herein, we determined that growth arrest and DNA-damage-inducible protein 45α (GADD45α) is decreased in radioresistant cervical cancer compared to radiosensitive cancer both in vitro and in vivo. In addition, silencing GADD45α prevents cervical cancer cells from undergoing radiation-induced DNA damage, cell cycle arrest, and apoptosis. More importantly, our data show that the overexpression of GADD45α significantly enhances the radiosensitivity of radioresistant cervical cancer cells. These data show that GADD45α decreases the cytoplasmic distribution of APE1, thereby enhancing the radiosensitivity of cervical cancer cells. Furthermore, we show that GADD45α inhibits the production of nitric oxide (NO), a nuclear APE1 export stimulator, by suppressing both endothelial NO synthase (eNOS) and inducible NO synthase (iNOS) in cervical cancer cells. In conclusion, our findings suggest that decreased GADD45α expression significantly contributes to the development of radioresistance and that ectopic expression of GADD45α sensitizes cervical cancer cells to radiotherapy. GADD45α inhibits the NO-regulated cytoplasmic localization of APE1 through inhibiting eNOS and iNOS, thereby enhancing the radiosensitivity of cervical cancer cells.

Molecular response to phototoxic stress of UVB-irradiated ketoprofen through arresting cell cycle in G2/M phase and inducing apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Shicheng; Mizu, Hideo; Yamauchi, Hitoshi

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 cdc2more » 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.« less

Methoxyacetic acid suppresses prostate cancer cell growth by inducing growth arrest and apoptosis

PubMed Central

Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; Patel, Neil K; Lu, Hua; Zeng, Shelya X; Wang, Guangdi; Zhang, Changde; You, Zongbing

2014-01-01

Methoxyacetic acid (MAA) is a primary metabolite of ester phthalates that are used in production of consumer products and pharmaceutical products. MAA causes embryo malformation and spermatocyte death through inhibition of histone deacetylases (HDACs). Little is known about MAA’s effects on cancer cells. In this study, two immortalized human normal prostatic epithelial cell lines (RWPE-1 and pRNS-1-1) and four human prostate cancer cell lines (LNCaP, C4-2B, PC-3, and DU-145) were treated with MAA at different doses and for different time periods. Cell viability, apoptosis, and cell cycle analysis were performed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR, Western blot, and chromatin immunoprecipitation analyses. We found that MAA dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. MAA-induced apoptosis was due to down-regulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2, also named cIAP1), leading to activation of caspases 7 and 3 and turning on the downstream apoptotic events. MAA-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and CDK2 expression at the late time. MAA up-regulated p21 expression through inhibition of HDAC activities, independently of p53/p63/p73. These findings demonstrate that MAA suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which suggests that MAA could be used as a potential therapeutic drug for prostate cancer. PMID:25606576

Exposure cell number during feeder cell growth-arrest by Mitomycin C is a critical pharmacological aspect in stem cell culture system.

PubMed

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

2016-01-01

Growth-arrested feeder cells following Mitomycin C treatment are instrumental in stem cell culture allowing development of regenerative strategies and alternatives to animal testing in drug discovery. The concentration of Mitomycin C and feeder cell type was described to affect feeder performance but the criticality of feeder cell exposure density was not addressed. We hypothesize that the exposure cell density influences the effectiveness of Mitomycin C in an arithmetic manner. Three different exposure cell densities of Swiss 3T3 fibroblasts were treated with a range of Mitomycin C concentrations for 2h. The cells were replaced and the viable cells counted on 3, 6, 9, 12 and 20days. The cell extinctions were compared with doses per cell which were derived by dividing the product of concentration and volume of Mitomycin C solution with exposure cell number. The periodic post-treatment feeder cell extinctions were not just dependent on Mitomycin C concentration but also on dose per cell. Analysis of linearity between viable cell number and Mitomycin C dose per cell derived from the concentrations of 3 to 10μg/ml revealed four distinct categories of growth-arrest. Confluent cultures exposed to low concentration showed growth-arrest failure. The in vitro cell density titration can facilitate prediction of a compound's operational in vivo dosing. For containing the growth arrest failure, an arithmetic volume derivation strategy is proposed by fixing the exposure density to a safe limit. The feeder extinction characteristics are critical for streamlining the stem cell based pharmacological and toxicological assays. Copyright © 2016 Elsevier Inc. All rights reserved.

Spectral analysis-based risk score enables early prediction of mortality and cerebral performance in patients undergoing therapeutic hypothermia for ventricular fibrillation and comatose status

PubMed Central

Filgueiras-Rama, David; Calvo, Conrado J.; Salvador-Montañés, Óscar; Cádenas, Rosalía; Ruiz-Cantador, Jose; Armada, Eduardo; Rey, Juan Ramón; Merino, J.L.; Peinado, Rafael; Pérez-Castellano, Nicasio; Pérez-Villacastín, Julián; Quintanilla, Jorge G.; Jiménez, Santiago; Castells, Francisco; Chorro, Francisco J.; López-Sendón, J.L.; Berenfeld, Omer; Jalife, José; López de Sá, Esteban; Millet, José

2017-01-01

Background Early prognosis in comatose survivors after cardiac arrest due to ventricular fibrillation (VF) is unreliable, especially in patients undergoing mild hypothermia. We aimed at developing a reliable risk-score to enable early prediction of cerebral performance and survival. Methods Sixty-one out of 239 consecutive patients undergoing mild hypothermia after cardiac arrest, with eventual return of spontaneous circulation (ROSC), and comatose status on admission fulfilled the inclusion criteria. Background clinical variables, VF time and frequency domain fundamental variables were considered. The primary and secondary outcomes were a favorable neurological performance (FNP) during hospitalization and survival to hospital discharge, respectively. The predictive model was developed in a retrospective cohort (n=32; September 2006–September 2011, 48.5 ± 10.5 months of follow-up) and further validated in a prospective cohort (n = 29; October 2011–July 2013, 5 ± 1.8 months of follow-up). Results FNP was present in 16 (50.0%) and 21 patients (72.4%) in the retrospective and prospective cohorts, respectively. Seventeen (53.1%) and 21 patients (72.4%), respectively, survived to hospital discharge. Both outcomes were significantly associated (p < 0.001). Retrospective multivariate analysis provided a prediction model (sensitivity= 0.94, specificity = 1) that included spectral dominant frequency, derived power density and peak ratios between high and low frequency bands, and the number of shocks delivered before ROSC. Validation on the prospective cohort showed sensitivity = 0.88 and specificity = 0.91. A model-derived risk-score properly predicted 93% of FNP. Testing the model on follow-up showed a c-statistic ≥ 0.89. Conclusions A spectral analysis-based model reliably correlates time-dependent VF spectral changes with acute cerebral injury in comatose survivors undergoing mild hypothermia after cardiac arrest. PMID:25828128

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fournier, Marcia V.; Martin, Katherine J.; Kenny, Paraic A.

To understand how non-malignant human mammary epithelial cells (HMEC) transit from a disorganized proliferating to an organized growth arrested state, and to relate this process to the changes that occur in breast cancer, we studied gene expression changes in non-malignant HMEC grown in three-dimensional cultures, and in a previously published panel of microarray data for 295 breast cancer samples. We hypothesized that the gene expression pattern of organized and growth arrested mammary acini would share similarities with breast tumors with good prognoses. Using Affymetrix HG-U133A microarrays, we analyzed the expression of 22,283 gene transcripts in two HMEC cell lines, 184more » (finite life span) and HMT3522 S1 (immortal non-malignant), on successive days post-seeding in a laminin-rich extracellular matrix assay. Both HMECs underwent growth arrest in G0/G1 and differentiated into polarized acini between days 5 and 7. We identified gene expression changes with the same temporal pattern in both lines. We show that genes that are significantly lower in the organized, growth arrested HMEC than in their proliferating counterparts can be used to classify breast cancer patients into poor and good prognosis groups with high accuracy. This study represents a novel unsupervised approach to identifying breast cancer markers that may be of use clinically.« less

Perioperative cardiac arrest: an evolutionary analysis of the intra-operative cardiac arrest incidence in tertiary centers in Brazil.

PubMed

Vane, Matheus Fachini; do Prado Nuzzi, Rafael Ximenes; Aranha, Gustavo Fabio; da Luz, Vinicius Fernando; Sá Malbouisson, Luiz Marcelo; Gonzalez, Maria Margarita Castro; Auler, José Otávio Costa; Carmona, Maria José Carvalho

2016-01-01

Great changes in medicine have taken place over the last 25 years worldwide. These changes in technologies, patient risks, patient profile, and laws regulating the medicine have impacted the incidence of cardiac arrest. It has been postulated that the incidence of intraoperative cardiac arrest has decreased over the years, especially in developed countries. The authors hypothesized that, as in the rest of the world, the incidence of intraoperative cardiac arrest is decreasing in Brazil, a developing country. The aim of this study was to search the literature to evaluate the publications that relate the incidence of intraoperative cardiac arrest in Brazil and analyze the trend in the incidence of intraoperative cardiac arrest. There were 4 articles that met our inclusion criteria, resulting in 204,072 patients undergoing regional or general anesthesia in two tertiary and academic hospitals, totalizing 627 cases of intraoperative cardiac arrest. The mean intraoperative cardiac arrest incidence for the 25 years period was 30.72:10,000 anesthesias. There was a decrease from 39:10,000 anesthesias to 13:10,000 anesthesias in the analyzed period, with the related lethality from 48.3% to 30.8%. Also, the main causes of anesthesia-related cause of mortality changed from machine malfunction and drug overdose to hypovolemia and respiratory causes. There was a clear reduction in the incidence of intraoperative cardiac arrest in the last 25 years in Brazil. This reduction is seen worldwide and might be a result of multiple factors, including new laws regulating the medicine in Brazil, incorporation of technologies, better human development level of the country, and better patient care. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Identification and characterization of a translation arrest motif in VemP by systematic mutational analysis.

PubMed

Mori, Hiroyuki; Sakashita, Sohei; Ito, Jun; Ishii, Eiji; Akiyama, Yoshinori

2018-02-23

VemP ( V ibrio protein e xport m onitoring p olypeptide) is a secretory protein comprising 159 amino acid residues, which functions as a secretion monitor in Vibrio and regulates expression of the downstream V.secDF2 genes. When VemP export is compromised, its translation specifically undergoes elongation arrest at the position where the Gln 156 codon of vemP encounters the P-site in the translating ribosome, resulting in up-regulation of V.SecDF2 production. Although our previous study suggests that many residues in a highly conserved C-terminal 20-residue region of VemP contribute to its elongation arrest, the exact role of each residue remains unclear. Here, we constructed a reporter system to easily and exactly monitor the in vivo arrest efficiency of VemP. Using this reporter system, we systematically performed a mutational analysis of the 20 residues (His 138 -Phe 157 ) to identify and characterize the arrest motif. Our results show that 15 residues in the conserved region participate in elongation arrest and that multiple interactions between important residues in VemP and in the interior of the exit tunnel contribute to the elongation arrest of VemP. The arrangement of these important residues induced by specific secondary structures in the ribosomal tunnel is critical for the arrest. Pro scanning analysis of the preceding segment (Met 120 -Phe 137 ) revealed a minor role of this region in the arrest. Considering these results, we conclude that the arrest motif in VemP is mainly composed of the highly conserved multiple residues in the C-terminal region. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

The Flavonoid Apigenin Downregulates CDK1 by Directly Targeting Ribosomal Protein S9

PubMed Central

Iizumi, Yosuke; Oishi, Masakatsu; Taniguchi, Tomoyuki; Goi, Wakana; Sowa, Yoshihiro; Sakai, Toshiyuki

2013-01-01

Flavonoids have been reported to inhibit tumor growth by causing cell cycle arrest. However, little is known about the direct targets of flavonoids in tumor growth inhibition. In the present study, we developed a novel method using magnetic FG beads to purify flavonoid-binding proteins, and identified ribosomal protein S9 (RPS9) as a binding partner of the flavonoid apigenin. Similar to treatment with apigenin, knockdown of RPS9 inhibited the growth of human colon cancer cells at the G2/M phase by downregulating cyclin-dependent kinase 1 (CDK1) expression at the promoter level. Furthermore, knockdown of RPS9 suppressed G2/M arrest caused by apigenin. These results suggest that apigenin induces G2/M arrest at least partially by directly binding and inhibiting RPS9 which enhances CDK1 expression. We therefore raise the possibility that identification of the direct targets of flavonoids may contribute to the discovery of novel molecular mechanisms governing tumor growth. PMID:24009741

Estrogen suppresses breast cancer proliferation through GPER / p38 MAPK axis during hypoxia.

PubMed

Sathya, S; Sudhagar, S; Lakshmi, B S

2015-12-05

Breast cancer cells frequently experience hypoxia which is associated with resistance to hormonal therapy and poor clinical prognosis, making it important to understand the function of estrogen under hypoxic condition. Here, we demonstrate that estrogen suppresses breast cancer cell growth under hypoxia, through inhibition at G1/S phase of cell cycle, by elevation of p21 expression. The involvement of GPER in estrogen mediated growth arrest was elucidated using specific ligands and siRNA. Although, estrogen was observed to activate both p44/42 and p38 MAPK signaling, pharmacological inhibition and silencing of p38 MAPK abrogated the induction of p21 expression and growth arrest, during hypoxia. The involvement of estrogen induced ROS in the p38 MAPK mediated p21 expression and cell growth arrest was established by observing that scavenging of ROS by NAC abrogated p38 MAPK activation and p21 expression during hypoxia. In conclusion, Estrogen suppresses breast cancer growth by inhibiting G1/S phase transition through GPER/ROS/p38 MAPK/p21 mediated signaling during hypoxic condition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Discrete statistical model of fatigue crack growth in a Ni-base superalloy, capable of life prediction

NASA Astrophysics Data System (ADS)

Boyd-Lee, Ashley; King, Julia

1992-07-01

A discrete statistical model of fatigue crack growth in a nickel base superalloy Waspaloy, which is quantitative from the start of the short crack regime to failure, is presented. Instantaneous crack growth rate distributions and persistence of arrest distributions are used to compute fatigue lives and worst case scenarios without extrapolation. The basis of the model is non-material specific, it provides an improved method of analyzing crack growth rate data. For Waspaloy, the model shows the importance of good bulk fatigue crack growth resistance to resist early short fatigue crack growth and the importance of maximizing crack arrest both by the presence of a proportion of small grains and by maximizing grain boundary corrugation.

Temperature variability during targeted temperature management is not associated with neurological outcomes following cardiac arrest.

PubMed

Nayeri, Arash; Bhatia, Nirmanmoh; Holmes, Benjamin; Borges, Nyal; Armstrong, William; Xu, Meng; Farber-Eger, Eric; Wells, Quinn S; McPherson, John A

2017-06-01

Recent studies on comatose survivors of cardiac arrest undergoing targeted temperature management (TTM) have shown similar outcomes at multiple target temperatures. However, details regarding core temperature variability during TTM and its prognostic implications remain largely unknown. We sought to assess the association between core temperature variability and neurological outcomes in patients undergoing TTM following cardiac arrest. We analyzed a prospectively collected cohort of 242 patients treated with TTM following cardiac arrest at a tertiary care hospital between 2007 and 2014. Core temperature variability was defined as the statistical variance (i.e. standard deviation squared) amongst all core temperature recordings during the maintenance phase of TTM. Poor neurological outcome at hospital discharge, defined as a Cerebral Performance Category (CPC) score>2, was the primary outcome. Death prior to hospital discharge was assessed as the secondary outcome. Multivariable logistic regression was used to examine the association between temperature variability and neurological outcome or death at hospital discharge. A poor neurological outcome was observed in 147 (61%) patients and 136 (56%) patients died prior to hospital discharge. In multivariable logistic regression, increased core temperature variability was not associated with increased odds of poor neurological outcomes (OR 0.38, 95% CI 0.11-1.38, p=0.142) or death (OR 0.43, 95% CI 0.12-1.53, p=0.193) at hospital discharge. In this study, individual core temperature variability during TTM was not associated with poor neurological outcomes or death at hospital discharge. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed Central

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

2015-01-01

UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) recruits DNMT1 to hemimethylated DNA during replication and is essential for maintaining DNA methylation. uhrf1 mutant zebrafish have global DNA hypomethylation and display embryonic defects, including a small liver, and they die as larvae. We make the surprising finding that, despite their reduced organ size, uhrf1 mutants express high levels of genes controlling S-phase and have many more cells undergoing DNA replication, as measured by BrdU incorporation. In contrast to wild-type hepatocytes, which are continually dividing during hepatic outgrowth and thus dilute the BrdU label, uhrf1 mutant hepatocytes retain BrdU throughout outgrowth, reflecting cell cycle arrest. Pulse-chase-pulse experiments with BrdU and EdU, and DNA content analysis indicate that uhrf1 mutant cells undergo DNA re-replication and that apoptosis is the fate of many of the re-replicating and arrested hepatocytes. Importantly, the DNA re-replication phenotype and hepatic outgrowth failure are preceded by global loss of DNA methylation. Moreover, uhrf1 mutants are phenocopied by mutation of dnmt1, and Dnmt1 knockdown in uhrf1 mutants enhances their small liver phenotype. Together, these data indicate that unscheduled DNA replication and failed cell cycle progression leading to apoptosis are the mechanisms by which DNA hypomethylation prevents organ expansion in uhrf1 mutants. We propose that cell cycle arrest leading to apoptosis is a strategy that restricts propagation of epigenetically damaged cells during embryogenesis. PMID:25564650

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

PubMed

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

2015-02-01

UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) recruits DNMT1 to hemimethylated DNA during replication and is essential for maintaining DNA methylation. uhrf1 mutant zebrafish have global DNA hypomethylation and display embryonic defects, including a small liver, and they die as larvae. We make the surprising finding that, despite their reduced organ size, uhrf1 mutants express high levels of genes controlling S-phase and have many more cells undergoing DNA replication, as measured by BrdU incorporation. In contrast to wild-type hepatocytes, which are continually dividing during hepatic outgrowth and thus dilute the BrdU label, uhrf1 mutant hepatocytes retain BrdU throughout outgrowth, reflecting cell cycle arrest. Pulse-chase-pulse experiments with BrdU and EdU, and DNA content analysis indicate that uhrf1 mutant cells undergo DNA re-replication and that apoptosis is the fate of many of the re-replicating and arrested hepatocytes. Importantly, the DNA re-replication phenotype and hepatic outgrowth failure are preceded by global loss of DNA methylation. Moreover, uhrf1 mutants are phenocopied by mutation of dnmt1, and Dnmt1 knockdown in uhrf1 mutants enhances their small liver phenotype. Together, these data indicate that unscheduled DNA replication and failed cell cycle progression leading to apoptosis are the mechanisms by which DNA hypomethylation prevents organ expansion in uhrf1 mutants. We propose that cell cycle arrest leading to apoptosis is a strategy that restricts propagation of epigenetically damaged cells during embryogenesis. © 2015. Published by The Company of Biologists Ltd.

The B55α Regulatory Subunit of Protein Phosphatase 2A Mediates Fibroblast Growth Factor-Induced p107 Dephosphorylation and Growth Arrest in Chondrocytes

PubMed Central

Daempfling, Lea

2013-01-01

Fibroblast growth factor (FGF)-induced growth arrest of chondrocytes is a unique cell type-specific response which contrasts with the proliferative response of most cell types and underlies several genetic skeletal disorders caused by activating FGF receptor (FGFR) mutations. We have shown that one of the earliest key events in FGF-induced growth arrest is dephosphorylation of the retinoblastoma protein (Rb) family member p107 by protein phosphatase 2A (PP2A), a ubiquitously expressed multisubunit phosphatase. In this report, we show that the PP2A-B55α holoenzyme (PP2A containing the B55α subunit) is responsible for this phenomenon. Only the B55α (55-kDa regulatory subunit, alpha isoform) regulatory subunit of PP2A was able to bind p107, and this interaction was induced by FGF in chondrocytes but not in other cell types. Small interfering RNA (siRNA)-mediated knockdown of B55α prevented p107 dephosphorylation and FGF-induced growth arrest of RCS (rat chondrosarcoma) chondrocytes. Importantly, the B55α subunit bound with higher affinity to dephosphorylated p107. Since the p107 region interacting with B55α is also the site of cyclin-dependent kinase (CDK) binding, B55α association may also prevent p107 phosphorylation by CDKs. FGF treatment induces dephosphorylation of the B55α subunit itself on several serine residues that drastically increases the affinity of B55α for the PP2A A/C dimer and p107. Together these observations suggest a novel mechanism of p107 dephosphorylation mediated by activation of PP2A through B55α dephosphorylation. This mechanism might be a general signal transduction pathway used by PP2A to initiate cell cycle arrest when required by external signals. PMID:23716589

Molecular cloning of TA16, a transcriptional repressor that may mediate glucocorticoid-induced growth arrest of leiomyosarcoma cells.

PubMed

Fan, W; Ma, J X; Cheng, L; Norris, J S

1997-08-01

The DDT1 MF2 smooth muscle tumor cell line was derived from an estrogen/androgen-induced leiomyosarcoma that arose in the ductus deferens of a Syrian hamster. The growth of this cell line is arrested at the G0/G1 phase of the cell cycle after treatment with glucocorticoids. To identify the putative gene(s) that are potentially involved in this hormone-induced cell growth arrest, we have used a differential screening technique to clone those genes whose expression is induced or up-regulated by glucocorticoids. A number of glucocorticoid response genes were thereby isolated from the leiomyosarcoma cells. One of these clones, termed TA16, was found to be markedly up-regulated by glucocorticoids in DDT1 MF2 cells, but only marginally changed in GR1 cells, a glucocorticoid-resistant variant that was selected from the wild type DDT1 MF2 cell. Isolation and sequencing of its intact cDNA indicated that the TA16 encodes a protein 485 amino acids long, and its sequence is closely homologous to a novel transcriptional repressor that presumably represses the transcription activity of some zinc finger transcriptional factors through a direct interaction. Transfection assays demonstrated that introduction of an antisense TA16 cDNA expression vector, controlled by an MMTV promoter, into the DDT1 MF2 cell significantly relieved the glucocorticoid-induced cell growth arrest. This finding suggests that TA16 might participate in the mediation of glucocorticoid-induced cell cycle arrest in leiomyosarcoma cells.

Mechanisms of palatal epithelial seam disintegration by Transforming Growth Factor (TGF)-β3

PubMed Central

Ahmed, Shaheen; Liu, Chang-Chih; Nawshad, Ali

2007-01-01

TGFβ3 signaling initiates and completes sequential phases of cellular differentiation that is required for complete disintegration of the palatal medial edge seam, that progresses between 14 to 17 embryonic days in the murine system, which is necessary in establishing confluence of the palatal stroma. Understanding the cellular mechanism of palatal MES disintegration in response to TGFβ3 signaling will result in new approaches to defining the causes of cleft palate and other facial clefts that may result from failure of seam disintegration. We have isolated MES primary cells to study the details of MES disintegration mechanism by TGFβ3 during palate development using several biochemical and genetic approaches. Our results demonstrate a novel mechanism of MES disintegration where MES, independently yet sequentially, undergoes cell cycle arrest, cell migration and apoptosis to generate immaculate palatal confluency during palatogenesis in response to robust TGFβ3 signaling. The results contribute to a missing fundamental element to our base knowledge of the diverse roles of TGFβ3 in functional and morphological changes that MES undergo during palatal seam disintegration. We believe that our findings will lead to more effective treatment of facial clefting. PMID:17698055

Targeted Repression of Essential Genes To Arrest Growth and Increase Carbon Partitioning and Biofuel Titers in Cyanobacteria.

PubMed

Shabestary, Kiyan; Anfelt, Josefine; Ljungqvist, Emil; Jahn, Michael; Yao, Lun; Hudson, Elton P

2018-06-08

Photoautotrophic production of fuels and chemicals by cyanobacteria typically gives lower volumetric productivities and titers than heterotrophic production. Cyanobacteria cultures become light limited above an optimal cell density, so that this substrate is not supplied to all cells sufficiently. Here, we investigate genetic strategies for a two-phase cultivation, where biofuel-producing Synechocystis cultures are limited to an optimal cell density through inducible CRISPR interference (CRISPRi) repression of cell growth. Fixed CO 2 is diverted to ethanol or n-butanol. Among the most successful strategies was partial repression of citrate synthase gltA. Strong repression (>90%) of gltA at low culture densities increased carbon partitioning to n-butanol 5-fold relative to a nonrepression strain, but sacrificed volumetric productivity due to severe growth restriction. CO 2 fixation continued for at least 3 days after growth was arrested. By targeting sgRNAs to different regions of the gltA gene, we could modulate GltA expression and carbon partitioning between growth and product to increase both specific and volumetric productivity. These growth arrest strategies can be useful for improving performance of other photoautotrophic processes.

Mechanisms underlying the growth inhibitory effects of the cyclo-oxygenase-2 inhibitor celecoxib in human breast cancer cells

PubMed Central

Basu, Gargi D; Pathangey, Latha B; Tinder, Teresa L; Gendler, Sandra J; Mukherjee, Pinku

2005-01-01

Introduction Inhibitors of cyclo-oxygenase (COX)-2 are being extensively studied as anticancer agents. In the present study we evaluated the mechanisms by which a highly selective COX-2 inhibitor, celecoxib, affects tumor growth of two differentially invasive human breast cancer cell lines. Methods MDA-MB-231 (highly invasive) and MDA-MB-468 (moderately invasive) cell lines were treated with varying concentrations of celecoxib in vitro, and the effects of this agent on cell growth and angiogenesis were monitored by evaluating cell proliferation, apoptosis, cell cycle arrest, and vasculogenic mimicry. The in vitro results of MDA-MB-231 cell line were further confirmed in vivo in a mouse xenograft model. Results The highly invasive MDA-MB-231 cells express higher levels of COX-2 than do the less invasive MDA-MB-468 cells. Celecoxib treatment inhibited COX-2 activity, indicated by prostaglandin E2 secretion, and caused significant growth arrest in both breast cancer cell lines. In the highly invasive MDA-MB-231 cells, the mechanism of celecoxib-induced growth arrest was by induction of apoptosis, associated with reduced activation of protein kinase B/Akt, and subsequent activation of caspases 3 and 7. In the less invasive MDA-MB-468 cells, growth arrest was a consequence of cell cycle arrest at the G0/G1 checkpoint. Celecoxib-induced growth inhibition was reversed by addition of exogenous prostaglandin E2 in MDA-MB-468 cells but not in MDA-MB-231 cells. Furthermore, MDA-MB-468 cells formed significantly fewer extracellular matrix associated microvascular channels in vitro than did the high COX-2 expressing MDA-MB-231 cells. Celecoxib treatment not only inhibited cell growth and vascular channel formation but also reduced vascular endothelial growth factor levels. The in vitro findings corroborated in vivo data from a mouse xenograft model in which daily administration of celecoxib significantly reduced tumor growth of MDA-MB-231 cells, which was associated with reduced vascularization and increased necrosis in the tumor mass. Conclusion The disparate molecular mechanisms of celecoxib-induced growth inhibition in human breast cancer cells depends upon the level of COX-2 expression and the invasive potential of the cell lines examined. Data suggest a role for COX-2 not only in the growth of cancer cells but also in activating the angiogenic pathway through regulating levels of vascular endothelial growth factor. PMID:15987447

Indeterminate Growth: Could It Represent the Ancestral Condition?

PubMed Central

Hariharan, Iswar K.; Wake, David B.; Wake, Marvalee H.

2016-01-01

Although we are used to the idea that many organisms stop growing when they reach a predictable size, in many taxa, growth occurs throughout the life of an organism, a phenomenon referred to as indeterminate growth. Our comparative analysis suggests that indeterminate growth may indeed represent the ancestral condition, whereas the permanent arrest of growth may be a more derived state. Consistent with this idea, in diverse taxa, the basal branches show indeterminate growth, whereas more derived branches arrest their growth. Importantly, in some closely related taxa, the termination of growth has evolved in mechanistically distinct ways. Also, even within a single organism, different organs can differ with respect to whether they terminate their growth or not. Finally, the study of tooth development indicates that, even at the level of a single tissue, multiple determinate patterns of growth can evolve from an ancestral one that is indeterminate. PMID:26216720

Cigarette smoke-induced cell cycle arrest in spermatocytes [GC-2spd(ts)] is mediated through crosstalk between Ahr-Nrf2 pathway and MAPK signaling.

PubMed

Esakky, Prabagaran; Hansen, Deborah A; Drury, Andrea M; Moley, Kelle H

2015-02-01

Our earlier studies have demonstrated that the cigarette smoke in the form of cigarette smoke condensate (CSC) causes growth arrest of a mouse spermatocyte cell line [GC-2spd(ts)] through activation of the AHR-NRF2 pathway. The present study demonstrates the CSC-activated p38 and ERK MAPK signaling in GC-2spd(ts) via arylhydrocarbon receptor (AHR). Pharmacological inhibition by using AHR-antagonist, or p38 MAPK and ERK (MEK1) inhibitors significantly abrogates CSC-induced growth arrest by AHR and MAPK inactivation. QRT-PCR, western blot, and immunofluorescence of Ahr-target of Nrf2, and stress-inducible growth suppressive Atf3 and E2f4 following treatments indicate a crosstalk among these pathways. Regulation of Atf3 by Nrf2 and Ahr through RNA interference suggests the existence of a cross-regulatory loop between the targets. CSC induction of E2f4 via Atf3 and its regulation by pharmacological inhibitors reveal a possible regulatory mechanism of growth inhibitory CSC. SiRNA silencing of Ahr, Nrf2, Atf3, and E2f4 genes and downregulation of cyclins by CSC corroborate the growth inhibitory effect of cigarette smoke. Thus, the data obtained suggest that the CSC-mediated MAPKs and AHR-NRF2 crosstalks lay the molecular basis for the growth arrest and cell death of spermatocytes. © The Author (2014). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

Induction of miR-137 by Isorhapontigenin (ISO) Directly Targets Sp1 Protein Translation and Mediates Its Anticancer Activity Both In Vitro and In Vivo.

PubMed

Zeng, Xingruo; Xu, Zhou; Gu, Jiayan; Huang, Haishan; Gao, Guangxun; Zhang, Xiaoru; Li, Jingxia; Jin, Honglei; Jiang, Guosong; Sun, Hong; Huang, Chuanshu

2016-03-01

Our recent studies found that isorhapontigenin (ISO) showed a significant inhibitory effect on human bladder cancer cell growth, accompanied with cell-cycle G0-G1 arrest as well as downregulation of Cyclin D1 expression at transcriptional level via inhibition of Sp1 transactivation in bladder cancer cells. In the current study, the potential ISO inhibition of bladder tumor formation has been explored in a xenograft nude mouse model, and the molecular mechanisms underlying ISO inhibition of Sp1 expression and anticancer activities have been elucidated both in vitro and in vivo. Moreover, the studies demonstrated that ISO treatment induced the expression of miR-137, which in turn suppressed Sp1 protein translation by directly targeting Sp1 mRNA 3'-untranslated region (UTR). Similar to ISO treatment, ectopic expression of miR-137 alone led to G0-G1 cell growth arrest and inhibition of anchorage-independent growth in human bladder cancer cells, which could be completely reversed by overexpression of GFP-Sp1. The inhibition of miR-137 expression attenuated ISO-induced inhibition of Sp1/Cyclin D1 expression, induction of G0-G1 cell growth arrest, and suppression of cell anchorage-independent growth. Taken together, our studies have demonstrated that miR-137 induction by ISO targets Sp1 mRNA 3'-UTR and inhibits Sp1 protein translation, which consequently results in reduction of Cyclin D1 expression, induction of G0-G1 growth arrest, and inhibition of anchorage-independent growth in vitro and in vivo. Our results have provided novel insights into understanding the anticancer activity of ISO in the therapy of human bladder cancer. ©2016 American Association for Cancer Research.

Induction of miR-137 by isorhapontigenin (ISO) direct targeted Sp1 protein translation and mediated its anti-cancer activity both in vitro and in vivo

PubMed Central

Zeng, Xingruo; Xu, Zhou; Gu, Jiayan; Huang, Haishan; Gao, Guangxun; Zhang, Xiaoru; Li, Jingxia; Jin, Honglei; Jiang, Guosong; Sun, Hong; Huang, Chuanshu

2016-01-01

Our recent studies found that isorhapontigenin (ISO) showed a significant inhibitory effect on human bladder cancer cell growth, accompanied with cell cycle G0/G1 arrest as well as down-regulation of Cyclin D1 expression at transcriptional level via inhibition of Sp1 transactivation in bladder cancer cells. In current studies, the potential ISO inhibition of bladder tumor formation has been explored in xenograft nude mouse model, and the molecular mechanisms underlying ISO inhibition of Sp1 expression and anti-cancer activities has been elucidated both in vitro and in vivo. Moreover, the studies demonstrated that ISO treatment induced the expression of miR-137, which in turn suppressed Sp1 protein translation by direct targeting Sp1 mRNA 3′UTR. Similar to ISO treatment, ectopic expression of miR-137 alone led to G0/G1 cell growth arrest and inhibition of anchorage-independent growth in human bladder cancer cells, which could be completely reversed by over-expression of GFP-Sp1. The inhibition of miR-137 expression attenuated ISO-induced the inhibition of Sp1/Cyclin D1 expression, and induction of G0/G1 cell growth arrest and suppression of cell anchorage-independent growth. Taken together, our studies have demonstrated that miR-137 induction by ISO targets Sp1 mRNA 3′UTR and inhibits Sp1 protein translation, which consequently results in reduction of Cyclin D1 expression, induction of G0/G1 growth arrest and inhibition of anchorage-independent growth in vitro and in vivo. Our results have provided novel insights into understanding the anti-cancer activity of ISO in the therapy of human bladder cancer. PMID:26832795

The Sep1 Mutant of Saccharomyces Cerevisiae Arrests in Pachytene and Is Deficient in Meiotic Recombination

PubMed Central

Tishkoff, D. X.; Rockmill, B.; Roeder, G. S.; Kolodner, R. D.

1995-01-01

Strand exchange protein 1 (Sep1) from Saccharomyces cerevisiae promotes homologous pairing of DNA in vitro and sep1 mutants display pleiotropic phenotypes in both vegetative and meiotic cells. In this study, we examined in detail the ability of the sep1 mutant to progress through meiosis I prophase and to undergo meiotic recombination. In meiotic return-to-growth experiments, commitment to meiotic recombination began at the same time in wild type and mutant; however, recombinants accumulated at decreased rates in the mutant. Gene conversion eventually reached nearly wild-type levels, whereas crossing over reached 15-50% of wild type. In an assay of intrachromosomal pop-out recombination, the sep1, dmc1 and rad51 single mutations had only small effects; however, pop-out recombination was virtually eliminated in the sep1 dmc1 and sep1 rad51 double mutants, providing evidence for multiple recombination pathways. Analysis of meiotic recombination intermediates indicates that the sep1 mutant is deficient in meiotic double-strand break repair. In a physical assay, the formation of mature reciprocal recombinants in the sep1 mutant was delayed relative to wild type and ultimately reached only 50% of the wild-type level. Electron microscopic analysis of meiotic nuclear spreads indicates that the sep1δ mutant arrests in pachytene, with apparently normal synaptonemal complex. This arrest is RAD9-independent. We hypothesize that the Sep1 protein participates directly in meiotic recombination and that other strand exchange enzymes, acting in parallel recombination pathways, are able to substitute partially for the absence of the Sep1 protein. PMID:7713413

Effect of primycin on growth-arrested cultures and cell integrity of Staphylococcus aureus.

PubMed

Feiszt, Péter; Schneider, György; Emődy, Levente

2017-06-01

Bactericidal effect against non-dividing bacteria is a very advantageous, but rare characteristic among antimicrobial agents, mostly possessed by those affecting the cell membrane. These kinds of agents can kill bacterial cells without lysis. We assessed these characteristics on primycin, a topical anti-staphylococcal agent highly effective against prevalent multiresistant strains, as it also acts on the cell membrane. In time-kill studies, primycin preserved its bactericidal activity against growth-arrested Staphylococcus aureus cultures. The bactericidal action was slower against growth-arrested cultures compared to the exponentially growing ones to different extents depending on the manner of arrest. The bactericidal effect was less influenced by stringent response and by protein synthesis inhibition, proving that it does not depend on metabolic activity. In contrast, uncoupling of the membrane potential predominantly slowed, and low temperature almost stopped killing of bacteria. In consideration of published data, these facts suggest that the antibacterial action of primycin involves disrupting of the membrane potential, and is predominantly influenced by the membrane fluidity. Optical density measurements and transmission electron microscopy verified that primycin kills bacterial cells without lysis. These results reveal favorable characteristics of primycin and point to, and broaden the knowledge on its membrane-targeted effect.

Negative regulation of G2-M by ATR (mei-41)/Chk1(Grapes) facilitates tracheoblast growth and tracheal hypertrophy in Drosophila.

PubMed

Kizhedathu, Amrutha; Bagul, Archit V; Guha, Arjun

2018-04-16

Imaginal progenitors in Drosophila are known to arrest in G2 during larval stages and proliferate thereafter. Here we investigate the mechanism and implications of G2 arrest in progenitors of the adult thoracic tracheal epithelium (tracheoblasts). We report that tracheoblasts pause in G2 for ~48-56 h and grow in size over this period. Surprisingly, tracheoblasts arrested in G2 express drivers of G2-M like Cdc25/String (Stg). We find that mechanisms that prevent G2-M are also in place in this interval. Tracheoblasts activate Checkpoint Kinase 1/Grapes (Chk1/Grp) in an ATR/mei-41-dependent manner. Loss of ATR/Chk1 led to precocious mitotic entry ~24-32 h earlier. These divisions were apparently normal as there was no evidence of increased DNA damage or cell death. However, induction of precocious mitoses impaired growth of tracheoblasts and the tracheae they comprise. We propose that ATR/Chk1 negatively regulate G2-M in developing tracheoblasts and that G2 arrest facilitates cellular and hypertrophic organ growth. © 2018, Kizhedathu et al.

Temporal dynamics of the Saccharopolyspora erythraea phosphoproteome.

PubMed

Licona-Cassani, Cuauhtemoc; Lim, Sooa; Marcellin, Esteban; Nielsen, Lars K

2014-05-01

Actinomycetes undergo a dramatic reorganization of metabolic and cellular machinery during a brief period of growth arrest ("metabolic switch") preceding mycelia differentiation and the onset of secondary metabolite biosynthesis. This study explores the role of phosphorylation in coordinating the metabolic switch in the industrial actinomycete Saccharopolyspora erythraea. A total of 109 phosphopeptides from 88 proteins were detected across a 150-h fermentation using open-profile two-dimensional LC-MS proteomics and TiO(2) enrichment. Quantitative analysis of the phosphopeptides and their unphosphorylated cognates was possible for 20 pairs that also displayed constant total protein expression. Enzymes from central carbon metabolism such as putative acetyl-coenzyme A carboxylase, isocitrate lyase, and 2-oxoglutarate dehydrogenase changed dramatically in the degree of phosphorylation during the stationary phase, suggesting metabolic rearrangement for the reutilization of substrates and the production of polyketide precursors. In addition, an enzyme involved in cellular response to environmental stress, trypsin-like serine protease (SACE_6340/NC_009142_6216), decreased in phosphorylation during the growth arrest stage. More important, enzymes related to the regulation of protein synthesis underwent rapid phosphorylation changes during this stage. Whereas the degree of phosphorylation of ribonuclease Rne/Rng (SACE_1406/NC_009142_1388) increased during the metabolic switch, that of two ribosomal proteins, S6 (SACE_7351/NC_009142_7233) and S32 (SACE_6101/NC_009142_5981), dramatically decreased during this stage of the fermentation, supporting the hypothesis that ribosome subpopulations differentially regulate translation before and after the metabolic switch. Overall, we show the great potential of phosphoproteomic studies to explain microbial physiology and specifically provide evidence of dynamic protein phosphorylation events across the developmental cycle of actinomycetes.

Temporal Dynamics of the Saccharopolyspora erythraea Phosphoproteome*

PubMed Central

Licona-Cassani, Cuauhtemoc; Lim, SooA; Marcellin, Esteban; Nielsen, Lars K.

2014-01-01

Actinomycetes undergo a dramatic reorganization of metabolic and cellular machinery during a brief period of growth arrest (“metabolic switch”) preceding mycelia differentiation and the onset of secondary metabolite biosynthesis. This study explores the role of phosphorylation in coordinating the metabolic switch in the industrial actinomycete Saccharopolyspora erythraea. A total of 109 phosphopeptides from 88 proteins were detected across a 150-h fermentation using open-profile two-dimensional LC-MS proteomics and TiO2 enrichment. Quantitative analysis of the phosphopeptides and their unphosphorylated cognates was possible for 20 pairs that also displayed constant total protein expression. Enzymes from central carbon metabolism such as putative acetyl-coenzyme A carboxylase, isocitrate lyase, and 2-oxoglutarate dehydrogenase changed dramatically in the degree of phosphorylation during the stationary phase, suggesting metabolic rearrangement for the reutilization of substrates and the production of polyketide precursors. In addition, an enzyme involved in cellular response to environmental stress, trypsin-like serine protease (SACE_6340/NC_009142_6216), decreased in phosphorylation during the growth arrest stage. More important, enzymes related to the regulation of protein synthesis underwent rapid phosphorylation changes during this stage. Whereas the degree of phosphorylation of ribonuclease Rne/Rng (SACE_1406/NC_009142_1388) increased during the metabolic switch, that of two ribosomal proteins, S6 (SACE_7351/NC_009142_7233) and S32 (SACE_6101/NC_009142_5981), dramatically decreased during this stage of the fermentation, supporting the hypothesis that ribosome subpopulations differentially regulate translation before and after the metabolic switch. Overall, we show the great potential of phosphoproteomic studies to explain microbial physiology and specifically provide evidence of dynamic protein phosphorylation events across the developmental cycle of actinomycetes. PMID:24615062

Differential effects of retinoic acid (RA) and N-(4-hydroxyphenyl) retinamide (4-HPR) on cell growth, induction of differentiation, and changes in p34cdc2, Bcl-2, and actin expression in the human promyelocytic HL-60 leukemic cells.

PubMed

Dipietrantonio, A; Hsieh, T C; Wu, J M

1996-07-25

Incubation of the HL-60 cells with 3 microM of RA and 4-HPR resulted in suppression of cell growth and decrease in cell viability. A significant percentage of the RA-treated cells also displayed differentiation towards neutrophils, as assayed by changes in nitroblue tetrazolium reduction (NBT) and alpha-naphthyl-acetate esterase (ANAE) activities, whereas the 4-HPR treated cells remained essentially undifferentiated. Flow cytometric analysis showed 4-HPR to cause partial cell arrest in the G2/M phase after a 3-day treatment and an additional G1 phase arrest after a 7-day treatment. With RA-treated cells, a reduction in the percentage of cells in the G1 phase was observed after 7 days of treatment. In 4-HPR-treated cells an extra peak, characteristic of cells undergoing apoptosis, was found in the cell cycle phase distribution analysis. Determination of specific protein expression changes by Western blot analysis showed that the p34cdc2 was down-regulated by both chemicals. Furthermore, RA induced bcl-2 but prevented the processing of actin, whereas 4-HPR had little effect on bcl-2 but increased the specific processing of actin. These results suggest that RA promotes neutrophil differentiation and the establishment of a semi apoptosis-resistant state, possibly through the overexpression of the bcl-2 gene. By contrast, 4-HPR may trigger apoptosis by inducing overall cyto-architectural changes and specific DNA fragmentation subsequent to increased turnover of the protein actin.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, Janmejai K.; Department of Urology, University Hospitals of Cleveland, Cleveland, OH 44106; Gupta, Sanjay

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 inmore » 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.« less

p-Dodecylaminophenol derived from the synthetic retinoid, fenretinide: antitumor efficacy in vitro and in vivo against human prostate cancer and mechanism of action.

PubMed

Takahashi, Noriko; Watanabe, Yusuke; Maitani, Yoshie; Yamauchi, Takayasu; Higashiyama, Kimio; Ohba, Toshihiro

2008-02-01

Fenretinide, N-(4-hydroxyphenyl)retinamide (4-HPR) is an aminophenol-containing synthetic retinoid derivative of all-trans-retinoic acid, which is a potent chemopreventive and antiproliferative agent against various cancers. Clinical studies of 4-HPR have shown side effects consisting of night blindness and ocular toxicity. To maintain potent anticancer activity without side effects, p-dodecylaminophenol (p-DDAP) was designed based on structure-activity relationships of 4-HPR. In our study, we investigate whether p-DDAP shows anticancer activity against human prostate cancer cell line PC-3 when compared with 4-HPR. p-DDAP inhibited PC-3 cell growth progressively from low to high concentration in a dose-dependent manner. p-DDAP was the most potent antiproliferative agent in vitro among 6 p-alkylaminophenols and 3 4-hydroxyphenyl analogs examined including 4-HPR. Cells treated with p-DDAP were shown to undergo apoptosis, based on condensation nuclei, cytofluorimetric analysis, propidium iodide staining and the expression of bcl-2 and caspase 3. p-DDAP arrested the S phase of the cell cycle, while 4-HPR arrested the G(0)/G(1) phase. In addition, both the i.v. and i.p. administration of p-DDAP suppressed tumor growth in PC-3-implanted mice in vivo. p-DDAP showed no effects on blood retinol concentrations, in contrast to reductions after 4-HPR administration. These results indicate that p-DDAP exhibits excellent anticancer efficacy against hormonal independent prostate cancer in vitro and in vivo, and it may have great potential for clinical use in the treatment of prostate cancer with reduced side effects. (c) 2007 Wiley-Liss, Inc.

Growth arrest by the antitumor steroidal lactone withaferin A in human breast cancer cells is associated with down-regulation and covalent binding at cysteine 303 of β-tubulin.

PubMed

Antony, Marie L; Lee, Joomin; Hahm, Eun-Ryeong; Kim, Su-Hyeong; Marcus, Adam I; Kumari, Vandana; Ji, Xinhua; Yang, Zhen; Vowell, Courtney L; Wipf, Peter; Uechi, Guy T; Yates, Nathan A; Romero, Guillermo; Sarkar, Saumendra N; Singh, Shivendra V

2014-01-17

Withaferin A (WA), a C5,C6-epoxy steroidal lactone derived from a medicinal plant (Withania somnifera), inhibits growth of human breast cancer cells in vitro and in vivo and prevents mammary cancer development in a transgenic mouse model. However, the mechanisms underlying the anticancer effect of WA are not fully understood. Herein, we report that tubulin is a novel target of WA-mediated growth arrest in human breast cancer cells. The G2 and mitotic arrest resulting from WA exposure in MCF-7, SUM159, and SK-BR-3 cells was associated with a marked decrease in protein levels of β-tubulin. These effects were not observed with the naturally occurring C6,C7-epoxy analogs of WA (withanone and withanolide A). A non-tumorigenic normal mammary epithelial cell line (MCF-10A) was markedly more resistant to mitotic arrest by WA compared with breast cancer cells. Vehicle-treated control cells exhibited a normal bipolar spindle with chromosomes aligned along the metaphase plate. In contrast, WA treatment led to a severe disruption of normal spindle morphology. NMR analyses revealed that the A-ring enone in WA, but not in withanone or withanolide A, was highly reactive with cysteamine and rapidly succumbed to irreversible nucleophilic addition. Mass spectrometry demonstrated direct covalent binding of WA to Cys(303) of β-tubulin in MCF-7 cells. Molecular docking indicated that the WA-binding pocket is located on the surface of β-tubulin and characterized by a hydrophobic floor, a hydrophobic wall, and a charge-balanced hydrophilic entrance. These results provide novel insights into the mechanism of growth arrest by WA in breast cancer cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Masatoshi, E-mail: msuzuki@nagasaki-u.ac.jp; Yamauchi, Motohiro; Oka, Yasuyoshi

Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% andmore » 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO{sub 2}-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ss-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.« less

Nanosecond pulsed electric fields and the cell cycle

NASA Astrophysics Data System (ADS)

Mahlke, Megan A.

Exposure to nanosecond pulsed electrical fields (nsPEFs) can cause poration of external and internal cell membranes, DNA damage, and disassociation of cytoskeletal components, all of which are capable of disrupting a cell's ability to replicate. The phase of the cell cycle at the time of exposure is linked to differential sensitivities to nsPEFs across cell lines, as DNA structure, membrane elasticity, and cytoskeletal structure change dramatically during the cell cycle. Additionally, nsPEFs are capable of activating cell cycle checkpoints, which could lead to apoptosis or slow population growth. NsPEFs are emerging as a method for treating tumors via apoptotic induction; therefore, investigating the relevance of nsPEFs and the cell cycle could translate into improved efficacy in tumor treatment. Populations of Jurkat and Chinese Hamster Ovary (CHO) cells were examined post-exposure (10 ns pulse trains at 150kV/cm) by analysis of DNA content via propidium iodide staining and flow cytometric analysis at various time points (1, 6, and 12h post-exposure) to determine population distribution in cell cycle phases. Additionally, CHO and Jurkat cells were synchronized in G1/S and G2/M phases, pulsed, and analyzed to evaluate the role of cell cycle phase in survival of nsPEFs. CHO populations appeared similar to sham populations post-nsPEFs but exhibited arrest in the G1 phase at 6h after exposure. Jurkat cells exhibited increased cell death after nsPEFs compared to CHO cells but did not exhibit checkpoint arrest at any observed time point. The G1/S phase checkpoint is partially controlled by the action of p53; the lack of an active p53 response in Jurkat cells could contribute to their ability to pass this checkpoint and resist cell cycle arrest. Both cell lines exhibited increased sensitivity to nsPEFs in G2/M phase. Live imaging of CHO cells after nsPEF exposure supports the theory of G1/S phase arrest, as a reduced number of cells undergo mitosis within 24 h when compared to sham treated cells. CHO cells undergoing mitosis after exposure also exhibit improper separation of chromatids which could indicate loss of function of the mitotic spindle checkpoint. Activation and loss of function of checkpoints in CHO but not Jurkat cells after nsPEF exposure suggests that activation of cell cycle checkpoints could be important in defining the character of cell line specific recovery after nsPEF exposure. Moreover, the increased sensitivity in G2/M phase exhibited by both cell lines indicates that cell cycle phase is an important consideration during nsPEF exposure, particularly when aiming to induce apoptosis.

Modeling Cancer Cell Growth Dynamics In vitro in Response to Antimitotic Drug Treatment

PubMed Central

Lorz, Alexander; Botesteanu, Dana-Adriana; Levy, Doron

2017-01-01

Investigating the role of intrinsic cell heterogeneity emerging from variations in cell-cycle parameters and apoptosis is a crucial step toward better informing drug administration. Antimitotic agents, widely used in chemotherapy, target exclusively proliferative cells and commonly induce a prolonged mitotic arrest followed by cell death via apoptosis. In this paper, we developed a physiologically motivated mathematical framework for describing cancer cell growth dynamics that incorporates the intrinsic heterogeneity in the time individual cells spend in the cell-cycle and apoptosis process. More precisely, our model comprises two age-structured partial differential equations for the proliferative and apoptotic cell compartments and one ordinary differential equation for the quiescent compartment. To reflect the intrinsic cell heterogeneity that governs the growth dynamics, proliferative and apoptotic cells are structured in “age,” i.e., the amount of time remaining to be spent in each respective compartment. In our model, we considered an antimitotic drug whose effect on the cellular dynamics is to induce mitotic arrest, extending the average cell-cycle length. The prolonged mitotic arrest induced by the drug can trigger apoptosis if the time a cell will spend in the cell cycle is greater than the mitotic arrest threshold. We studied the drug’s effect on the long-term cancer cell growth dynamics using different durations of prolonged mitotic arrest induced by the drug. Our numerical simulations suggest that at confluence and in the absence of the drug, quiescence is the long-term asymptotic behavior emerging from the cancer cell growth dynamics. This pattern is maintained in the presence of small increases in the average cell-cycle length. However, intermediate increases in cell-cycle length markedly decrease the total number of cells and can drive the cancer population to extinction. Intriguingly, a large “switch-on/switch-off” increase in the average cell-cycle length maintains an active cell population in the long term, with oscillating numbers of proliferative cells and a relatively constant quiescent cell number. PMID:28913178

Valproic acid exhibits different cell growth arrest effect in three HPV-positive/negative cervical cancer cells and possibly via inducing Notch1 cleavage and E6 downregulation.

PubMed

Feng, Shuyu; Yang, Yue; Lv, Jingyi; Sun, Lichun; Liu, Mingqiu

2016-07-01

We investigated the effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, and the mechanism of VPA-induced growth inhibition on three cervical cancer cell lines with different molecular and genetic background. We found that VPA induced proliferation suppression, cell apoptosis and cell cycle arrest in all tested cell lines, with an increase of Notch1 active form ICN1 as a tumor suppressor and its target gene HES1. Noteworthy, blocking of Notch signaling with DAPT resulted in growth inhibition in ICN1-overexpressing CaSki and HT-3 cells. Thus, endogenous Notch signaling may be necessary for survival of ICN1-overexpressing cervical cancer cell lines. Furthermore, G1 phase arrest was induced in HeLa and CaSki cells by VPA while G2 phase arrest was induced in HT-3 cells, suggesting different mechanism in this cycle arrest. We also found VPA suppressed oncogene E6 in a Notch-independent manner, and induced significant apoptosis in E6-overexpressing HPV positive CaSki cells. Cell morphological change was also observed in HeLa and HT-3 cell lines after VPA treatment with an upregulation of EMT transcription factor Snail1. Notch signaling inhibitor DAPT partly reversed VPA-induced Snail1 upregulation in HeLa cells. This discovery supports that VPA may induce EMT at least partly via Notch activation.

Acetate supplementation induces growth arrest of NG2/PDGFRα-positive oligodendroglioma-derived tumor-initiating cells.

PubMed

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

2013-01-01

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

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

PubMed Central

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

2013-01-01

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

Vascular endothelial growth factor upregulation in transient global ischemia induced by cardiac arrest and resuscitation in rat brain.

PubMed

Pichiule, P; Chávez, J C; Xu, K; LaManna, J C

1999-12-10

This study examined vascular endothelial growth factor (VEGF) expression in rat brain after reversible global cerebral ischemia produced by cardiac arrest and resuscitation. Three alternative splicing forms, VEGF(188), VEGF(164) and VEGF(120), were observed in cortex, hippocampus and brainstem by RT-PCR analysis. After 24 h of recovery from cardiac arrest, mRNA levels corresponding to VEGF(188) and VEGF(164) were significantly increased by about double in all the regions analyzed. These mRNA levels remained elevated at 24 and 48 h of recovery but returned to basal expression after 7 days of recovery. Changes in VEGF(120) expression after cardiac arrest did not reach statistical significance. VEGF protein expression measured by Western blot was also increased by about double at 24 and 48 h of recovery but returned to control levels after 7 days of recovery. VEGF immunohistochemistry localized this increased expression mostly associated with astrocytes. Considering its biological activity, VEGF induction after cardiac arrest and resuscitation may be responsible for the increased vascular permeability and the resultant vasogenic edema, found 24-48 h after reversible global ischemia.

Schizosaccharomyces pombe Hsk1p Is a Potential Cds1p Target Required for Genome Integrity

PubMed Central

Snaith, Hilary A.; Brown, Grant W.; Forsburg, Susan L.

2000-01-01

The fission yeast Hsk1p kinase is an essential activator of DNA replication. Here we report the isolation and characterization of a novel mutant allele of the gene. Consistent with its role in the initiation of DNA synthesis, hsk1ts genetically interacts with several S-phase mutants. At the restrictive temperature, hsk1ts cells suffer abnormal S phase and loss of nuclear integrity and are sensitive to both DNA-damaging agents and replication arrest. Interestingly, hsk1ts mutants released to the restrictive temperature after early S-phase arrest in hydroxyurea (HU) are able to complete bulk DNA synthesis but they nevertheless undergo an abnormal mitosis. These findings indicate a second role for hsk1 subsequent to HU arrest. Consistent with a later S-phase role, hsk1ts is synthetically lethal with Δrqh1 (RecQ helicase) or rad21ts (cohesin) mutants and suppressed by Δcds1 (RAD53 kinase) mutants. We demonstrate that Hsk1p undergoes Cds1p-dependent phosphorylation in response to HU and that it is a direct substrate of purified Cds1p kinase in vitro. These results indicate that the Hsk1p kinase is a potential target of Cds1p regulation and that its activity is required after replication initiation for normal mitosis. PMID:11027263

Development of the follicle complex and oocyte staging in red drum, Sciaenops ocellatus Linnaeus, 1776 (Perciformes, Sciaenidae).

PubMed

Grier, Harry J

2012-08-01

Pelagic egg development in red drum, Sciaenops ocellatus, is described using tiered staging. Based on mitosis and meiosis, there are five periods: Mitosis of Oogonia, Active Meiosis I, Arrested Meiosis I, Active Meiosis II, and Arrested Meiosis II. The Periods are divided into six stages: Mitotic Division of Oogonia, Chromatin Nucleolus, Primary Growth, Secondary Growth, Oocyte Maturation and Ovulation. The Chromatin Nucleolus Stage is divided into four steps: Leptotene, Zygotene, Pachytene, and Early Diplotene. Oocytes in the last step possess one nucleolus, dispersed chromatin with forming lampbrush chromosomes and lack basophilic ooplasm. The Primary Growth Stage, characterized by basophilic ooplasm and absence of yolk in oocytes, is divided into five steps: One-Nucleolus, Multiple Nucleoli, Perinucleolar, Oil Droplets, and Cortical Alveolar. During primary growth, the Balbiani body develops from nuage, enlarges and disperses throughout the ooplasm as both endoplasmic reticulum and Golgi develop within it. Secondary growth or vitellogenesis has three steps: Early Secondary Growth, Late Secondary Growth and Full-Grown. The Oocyte Maturation Stage, including ooplasmic and germinal vesicle maturation, has four steps: Eccentric Germinal Vesicle, Germinal Vesicle Migration, Germinal Vesicle Breakdown and Resumption of Meiosis when complete yolk hydration occurs. The period is Arrested Meiosis II. When folliculogenesis is completed, the ovarian follicle, an oocyte and encompassing follicle cells, is surrounded by a basement membrane and developing theca, all forming a follicle complex. After ovulation, a newly defined postovulatory follicle complex remains attached to the germinal epithelium. It is composed of a basement membrane that separates the postovulatory follicle from the postovulatory theca. Arrested Meiosis I encompasses primary and secondary growth (vitellogenesis) and includes most of oocyte maturation until the resumption of meiosis (Active Meiosis II). The last stage, Ovulation, is the emergence of the oocyte from the follicle when it becomes an egg or ovum. Copyright © 2012 Wiley Periodicals, Inc.

Rapid glass sponge expansion after climate-induced Antarctic ice shelf collapse.

PubMed

Fillinger, Laura; Janussen, Dorte; Lundälv, Tomas; Richter, Claudio

2013-07-22

Over 30% of the Antarctic continental shelf is permanently covered by floating ice shelves, providing aphotic conditions for a depauperate fauna sustained by laterally advected food. In much of the remaining Antarctic shallows (<300 m depth), seasonal sea-ice melting allows a patchy primary production supporting rich megabenthic communities dominated by glass sponges (Porifera, Hexactinellida). The catastrophic collapse of ice shelves due to rapid regional warming along the Antarctic Peninsula in recent decades has exposed over 23,000 km(2) of seafloor to local primary production. The response of the benthos to this unprecedented flux of food is, however, still unknown. In 2007, 12 years after disintegration of the Larsen A ice shelf, a first biological survey interpreted the presence of hexactinellids as remnants of a former under-ice fauna with deep-sea characteristics. Four years later, we revisited the original transect, finding 2- and 3-fold increases in glass sponge biomass and abundance, respectively, after only two favorable growth periods. Our findings, along with other long-term studies, suggest that Antarctic hexactinellids, locked in arrested growth for decades, may undergo boom-and-bust cycles, allowing them to quickly colonize new habitats. The cues triggering growth and reproduction in Antarctic glass sponges remain enigmatic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Delayed-onset Reversible Cortical Blindness after Resuscitation from Cardiac Arrest

PubMed Central

de Souza, Aaron; de Souza, Rainha J.; Pai Kakode, Varun R.

2017-01-01

We present a patient who presented with cortical blindness (CB) 1 week after repeated cardiac arrest while undergoing treatment for an acute myocardial infarction. He had been revived within 5 min in each instance and was apparently neurologically normal until presentation. Magnetic resonance imaging showed subtle hyperintensities on fluid-attenuated inversion recovery and diffusion-weighted imaging in both temporooccipital cortices. A rapid recovery over the next 2 weeks was remarkable for the appearance of metamorphopsia. CB may present even days to weeks after hypoxic-ischemic encephalopathy following cardiac arrest, even in patients apparently without immediate neurological sequelae. The pathogenesis of this phenomenon remains to be fully elucidated, but is likely to be due to delayed effects of anoxia on the occipital cortex and may be analogous to the previously described syndrome of delayed posthypoxic leukoencephalopathy. Prognosis for visual recovery appears to be good. PMID:28936091

Evodiamine Induces Cell Growth Arrest, Apoptosis and Suppresses Tumorigenesis in Human Urothelial Cell Carcinoma Cells.

PubMed

Shi, Chung-Sheng; Li, Jhy-Ming; Chin, Chih-Chien; Kuo, Yi-Hung; Lee, Ying-Ray; Huang, Yun-Ching

2017-03-01

Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities including vasodilatation, analgesia, anti-cardiovascular disease, anti-Alzheimer's disease, anti-inflammation, and anti-tumor activity. This study analyzes the anti-tumor effects of evodiamine on cellular growth, tumorigenesis, cell cycle and apoptosis induction of human urothelial cell carcinoma (UCC) cells. The present study showed that evodiamine significantly inhibited the proliferation of UCC cells in a dose- and time-dependent manner. Also, evodiamine suppressed the tumorigenesis of UCC cells in vitro. Moreover, evodiamine caused G 2 /M cell-cycle arrest and induced caspase-dependent apoptosis in UCC cells. Finally, we demonstrated that evodiamine exhibits better cytotoxic than 5-fluorouracil, a clinical chemotherapeutic drug, for UCC cells. Evodiamine induces growth inhibition, tumorigenesis suppression, cell-cycle arrest, and apoptosis induction in human UCC cells. Therefore, this agent displays a therapeutic potential for treating human UCC cells and is worthy for further investigation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Cardiac arrest upon induction of anesthesia in children with cardiomyopathy: an analysis of incidence and risk factors.

PubMed

Lynch, Johanne; Pehora, Carolyne; Holtby, Helen; Schwarz, Steven M; Taylor, Katherine

2011-09-01

It is thought that patients with cardiomyopathy have an increased risk of cardiac arrest on induction of anesthesia, but there is little available data. The purpose of this study was to identify the incidence and potential risk factors for cardiac arrest upon induction of anesthesia in children with cardiomyopathy in our institution. A retrospective chart review was performed. Eligible patients included patients admitted between 1998 and 2008 with the International Statistical Classification of Disease code for cardiomyopathy (ICD-9 code 425) who underwent airway intervention for sedation or general anesthesia in the operating room, cardiac diagnostic and interventional unit (CDIU) or intensive care unit. Patients undergoing emergency airway intervention following cardiovascular collapse were excluded. For each patient, we recorded patient demographics, disease severity, anesthesia location, and anesthetic technique. One hundred and twenty-nine patients with cardiomyopathy underwent a total of 236 anesthetic events, and four cardiac arrests were identified. One was related to bradycardia (HR<60), two were attributed to bradycardia in association with severe hypotension (systolic blood pressure<45), and the fourth arrest was related to isolated severe hypotension. Two occurred in the operating suite and two in the CDIU. There was no resulting mortality. One patient progressed to heart transplantation. Multiple combinations of anesthetic drugs were used for induction of anesthesia. We performed a review of the last 10 years of anesthesia events in children with cardiomyopathy. We report four cardiac arrests in two patients and 236 anesthetic events (1.7%). To the best of our knowledge, this is the largest review of these patients to date but is limited by its retrospective nature. The low cardiac arrest incidence prevents the identification of risk factors and the development of a cardiac arrest risk predictive clinical tool. © 2011 Blackwell Publishing Ltd.

Aortic arch reconstruction: deep and moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion.

PubMed

Wu, YanWen; Xiao, LiQiong; Yang, Ting; Wang, Lei; Chen, Xin

2017-07-01

To compare the effects of moderate and deep hypothermic circulatory arrest (DHCA) with selective antegrade cerebral perfusion (SACP) during aortic arch surgery in adult patients and to offer the evidence for the detection of the temperature which provides best brain protection in the subjects who accept aortic arch reconstruction surgery. A total of 109 patients undergoing surgery of the aortic arch were divided into the moderate hypothermic circulatory arrest group (Group I) and the deep hypothermic circulatory arrest group (Group II). We recorded the data of the patients and their cardiopulmonary bypass (CPB) time, aortic clamping time, SACP time and postoperative anesthetized recovery time, tracheal intubation time, time in the intensive care unit (ICU) and postoperative neurologic dysfunction. Patient characteristics were similar in the two groups. There were four patients who died in Group II and 1 patient in Group I. There were no significant differences in aortic clamping time of each group (111.4±58.4 vs. 115.9±16.2) min; SACP time (27.4±5.9 vs. 23.5±6.1) min of the moderate hypothermic circulatory arrest group and the deep hypothermic circulatory arrest group; there were significant differences in cardiopulmonary bypass time (207.4±20.9 vs. 263.8±22.6) min, postoperative anesthetized recovery time (19.0±11.1 vs. 36.8±25.3) hours, extubation time (46.4±15.1 vs. 64.4±6.0) hours; length of stay in the intensive care unit (ICU) (4.7±1.7 vs. 8±2.3) days and postoperative neurologic dysfunction in the two groups. Compared to deep hypothermic circulatory arrest, moderate hypothermic circulatory arrest can provide better brain protection and achieve good clinical results.

Curcumin induces growth-arrest and apoptosis in association with the inhibition of constitutively active JAK-STAT pathway in T cell leukemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajasingh, Johnson; Raikwar, Himanshu P.; Muthian, Gladson

2006-02-10

Adult T cell leukemia is an aggressive and frequently fatal malignancy that expressess constitutively activated growth-signaling pathways in association with deregulated growth and resistance to apoptosis. Curcumin (diferuloylmethane) is a naturally occurring yellow pigment, isolated from the rhizomes of the plant Curcuma longa that has traditionally been used in the treatment of injury and inflammation. But the effect and mechanism of action of curcumin on T cell leukemia is not known. To investigate the antitumor activity of curcumin in T cell leukemia, we examined its effect on constitutive phosphorylation of JAK and STAT proteins, proliferation, and apoptosis in HTLV-I-transformed Tmore » cell lines. HTLV-I-transformed T cell leukemia lines, MT-2, HuT-102, and SLB-1, express constitutively phosphorylated JAK3, TYK2, STAT3, and STAT5 signaling proteins. In vitro treatment with curcumin induced a dose-dependent decrease in JAK and STAT phosphorylation resulting in the induction of growth-arrest and apoptosis in T cell leukemia. The induction of growth-arrest and apoptosis in association with the blockade of constitutively active JAK-STAT pathway suggests this be a mechanism by which curcumin induces antitumor activity in T cell leukemia.« less

PKA and Epac synergistically inhibit smooth muscle cell proliferation

PubMed Central

Hewer, Richard C.; Sala-Newby, Graciela B.; Wu, Yih-Jer; Newby, Andrew C.; Bond, Mark

2011-01-01

Cyclic AMP signalling promotes VSMC quiescence in healthy vessels and during vascular healing following injury. Cyclic AMP inhibits VSMC proliferation via mechanisms that are not fully understood. We investigated the role of PKA and Epac signalling on cAMP-induced inhibition of VSMC proliferation. cAMP-mediated growth arrest was PKA-dependent. However, selective PKA activation with 6-Benzoyl-cAMP did not inhibit VSMC proliferation, indicating a requirement for additional pathways. Epac activation using the selective cAMP analogue 8-CPT-2′-O-Me-cAMP, did not affect levels of hyperphosphorylated Retinoblastoma (Rb) protein, a marker of G1-S phase transition, or BrdU incorporation, despite activation of the Epac-effector Rap1. However, 6-Benzoyl-cAMP and 8-CPT-2′-O-Me-cAMP acted synergistically to inhibit Rb-hyperphosphorylation and BrdU incorporation, indicating that both pathways are required for growth inhibition. Consistent with this, constitutively active Epac increased Rap1 activity and synergised with 6-Benzoyl-cAMP to inhibit VSMC proliferation. PKA and Epac synergised to inhibit phosphorylation of ERK and JNK. Induction of stellate morphology, previously associated with cAMP-mediated growth arrest, was also dependent on activation of both PKA and Epac. Rap1 inhibition with Rap1GAP or siRNA silencing did not negate forskolin-induced inhibition of Rb-hyperphosphorylation, BrdU incorporation or stellate morphology. This data demonstrates for the first time that Epac synergises with PKA via a Rap1-independent mechanism to mediate cAMP-induced growth arrest in VSMC. This work highlights the role of Epac as a major player in cAMP-dependent growth arrest in VSMC. PMID:20971121

Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

PubMed

Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

2016-02-01

Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis. © Society for Leukocyte Biology.

Androgen Regulation of p27 in the Normal and Neoplastic Prostate

DTIC Science & Technology

1999-09-01

IL-6 (50) or the flavanoid antioxidant silibinin (5 1) results in increased p27KIP’ expression associated with G1 arrest and neuroendocrine...Commun 257:609-614. 51. Zi X, Agarwal R 1999 Silibinin decreases prostate-specific antigen with cell growth inhibition via GI arrest, leading to

Ethanol-Glycerin Fixation with Thymol Conservation: A Potential Alternative to Formaldehyde and Phenol Embalming

ERIC Educational Resources Information Center

Hammer, Niels; Loffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

2012-01-01

Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For…

On the Stem Cell Origin of Cancer

PubMed Central

Sell, Stewart

2010-01-01

In each major theory of the origin of cancer—field theory, chemical carcinogenesis, infection, mutation, or epigenetic change—the tissue stem cell is involved in the generation of cancer. Although the cancer type is identified by the more highly differentiated cells in the cancer cell lineage or hierarchy (transit-amplifying cells), the property of malignancy and the molecular lesion of the cancer exist in the cancer stem cell. In the case of teratocarcinomas, normal germinal stem cells have the potential to become cancers if placed in an environment that allows expression of the cancer phenotype (field theory). In cancers due to chemically induced mutations, viral infections, somatic and inherited mutations, or epigenetic changes, the molecular lesion or infection usually first occurs in the tissue stem cells. Cancer stem cells then give rise to transit-amplifying cells and terminally differentiated cells, similar to what happens in normal tissue renewal. However, the major difference between cancer growth and normal tissue renewal is that whereas normal transit amplifying cells usually differentiate and die, at various levels of differentiation, the cancer transit-amplifying cells fail to differentiate normally and instead accumulate (ie, they undergo maturation arrest), resulting in cancer growth. PMID:20431026

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).

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

PubMed

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

2005-02-01

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

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

PubMed

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

2015-08-14

Parkin is a known tumor suppressor. However, the mechanism by which parkin acts as a tumor suppressor remains to be fully elucidated. Previously, we reported that parkin expression induces caspase-dependent apoptotic cell death in TNF-α-treated HeLa cells. However, at that time, we did not consider the involvement of parkin in cell cycle control. In the current study, we investigated whether parkin is involved in cell cycle regulation and suppression of cancer cell growth. In our cell cycle analyses, parkin expression induced G2/M cell cycle arrest in TNF-α-treated HeLa cells. To elucidate the mechanism(s) by which parkin induces this G2/M arrest, we analyzed cell cycle regulatory molecules involved in the G2/M transition. Parkin expression induced CDC2 phosphorylation which is known to inhibit CDC2 activity and cause G2/M arrest. Cyclin B1, which is degraded during the mitotic transition, accumulated in response to parkin expression, thereby indicating parkin-induced G2/M arrest. Next, we established that Myt1, which is known to phosphorylate and inhibit CDC2, increased following parkin expression. In addition, we found that parkin also induces increased Myt1 expression, G2/M arrest, and reduced cell viability in TNF-α-treated HCT15 cells. Furthermore, knockdown of parkin expression by parkin-specific siRNA decreased Myt1 expression and phosphorylation of CDC2 and resulted in recovered cell viability. These results suggest that parkin acts as a crucial molecule causing cell cycle arrest in G2/M, thereby suppressing tumor cell growth. Copyright © 2015 Elsevier Inc. All rights reserved.

Small Molecule DFPM Derivative-Activated Plant Resistance Protein Signaling in Roots Is Unaffected by EDS1 Subcellular Targeting Signal and Chemical Genetic Isolation of victr R-Protein Mutants

PubMed Central

Mevers, Emily; García, Ana V.; Highhouse, Samantha; Gerwick, William H.; Parker, Jane E.; Schroeder, Julian I.

2016-01-01

The small molecule DFPM ([5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione) was recently shown to trigger signal transduction via early effector-triggered immunity signaling genes including EDS1 and PAD4 in Arabidopsis thaliana accession Col-0. Chemical genetic analyses of A. thaliana natural variants identified the plant Resistance protein-like Toll/Interleukin1 Receptor (TIR)-Nucleotide Binding (NB)-Leucine-Rich Repeat (LRR) protein VICTR as required for DFPM-mediated root growth arrest. Here a chemical genetic screen for mutants which disrupt DFPM-mediated root growth arrest in the Col-0 accession identified new mutant alleles of the TIR-NB-LRR gene VICTR. One allele, victr-6, carries a Gly216-to-Asp mutation in the Walker A domain supporting an important function of the VICTR nucleotide binding domain in DFPM responses consistent with VICTR acting as a canonical Resistance protein. The essential nucleo-cytoplasmic regulator of TIR-NB-LRR-mediated effector-triggered immunity, EDS1, was reported to have both nuclear and cytoplasmic actions in pathogen resistance. DFPM was used to investigate the requirements for subcellular EDS1 localization in DFPM-mediated root growth arrest. EDS1-YFP fusions engineered to localize mainly in the cytoplasm or the nucleus by tagging with a nuclear export signal (NES) or a nuclear localization signal (NLS), respectively, were tested. We found that wild-type EDS1-YFP and both the NES and NLS-tagged EDS1 variants were induced by DFPM treatments and fully complemented eds1 mutant plants in root responses to DFPM, suggesting that enrichment of EDS1 in either compartment could confer DFPM-mediated root growth arrest. We further found that a light and O2-dependent modification of DFPM is necessary to mediate DFPM signaling in roots. Chemical analyses including Liquid Chromatography-Mass Spectrometry and High-Resolution Atmospheric Pressure Chemical Ionization Mass Spectrometry identified a DFPM modification product that is likely responsible for bioactivity mediating root growth arrest. We propose a chemical structure of this product and a possible reaction mechanism for DFPM modification. PMID:27219122

Human papillomavirus 16E6 and NFX1-123 potentiate notch signaling and differentiation without activating cellular arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vliet-Gregg, Portia A.; Hamilton, Jennifer R.; Katzenellenbogen, Rachel A., E-mail: rkatzen@uw.edu

High-risk human papillomavirus (HR HPV) oncoproteins bind host cell proteins to dysregulate and uncouple apoptosis, senescence, differentiation, and growth. These pathways are important for both the viral life cycle and cancer development. HR HPV16 E6 (16E6) interacts with the cellular protein NFX1-123, and they collaboratively increase the growth and differentiation master regulator, Notch1. In 16E6 expressing keratinocytes (16E6 HFKs), the Notch canonical pathway genes Hes1 and Hes5 were increased with overexpression of NFX1-123, and their expression was directly linked to the activation or blockade of the Notch1 receptor. Keratinocyte differentiation genes Keratin 1 and Keratin 10 were also increased, butmore » in contrast their upregulation was only indirectly associated with Notch1 receptor stimulation and was fully unlinked to growth arrest, increased p21{sup Waf1/CIP1}, or decreased proliferative factor Ki67. This leads to a model of 16E6, NFX1-123, and Notch1 differently regulating canonical and differentiation pathways and entirely uncoupling cellular arrest from increased differentiation. - Highlights: • 16E6 and NFX1-123 increased the Notch canonical pathway through Notch1. • 16E6 and NFX1-123 increased the differentiation pathway indirectly through Notch1. • 16E6 and NFX1-123 increased differentiation gene expression without growth arrest. • Increased NFX1-123 with 16E6 may create an ideal cellular phenotype for HPV.« less

Identification of Fitness Determinants during Energy-Limited Growth Arrest in Pseudomonas aeruginosa

PubMed Central

Basta, David W.; Bergkessel, Megan

2017-01-01

ABSTRACT Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen. Using transposon-insertion sequencing (Tn-seq), we identified fitness determinants in these two energy-limited states. Multiple genes encoding general functions like transcriptional regulation and energy generation were required for fitness during carbon or oxygen limitation, yet many specific genes, and thus specific activities, differed in their relevance between these states. For instance, the global regulator RpoS was required during both types of energy limitation, while other global regulators such as DksA and LasR were required only during carbon or oxygen limitation, respectively. Similarly, certain ribosomal and tRNA modifications were specifically required during oxygen limitation. We validated fitness defects during energy limitation using independently generated mutants of genes detected in our screen. Mutants in distinct functional categories exhibited different fitness dynamics: regulatory genes generally manifested a phenotype early, whereas genes involved in cell wall metabolism were required later. Together, these results provide a new window into how P. aeruginosa survives growth arrest. PMID:29184024

Normal Human Fibroblasts Are Resistant to RAS-Induced Senescence

PubMed Central

Benanti, Jennifer A.; Galloway, Denise A.

2004-01-01

Oncogenic stimuli are thought to induce senescence in normal cells in order to protect against transformation and to induce proliferation in cells with altered p53 and/or retinoblastoma (Rb) pathways. In human fibroblasts, RAS initiates senescence through upregulation of the cyclin-dependent kinase inhibitor p16INK4A. We show here that in contrast to cultured fibroblast strains, freshly isolated normal fibroblasts are resistant to RAS-induced senescence and instead show some characteristics of transformation. RAS did not induce growth arrest or expression of senescence-associated β-galactosidase, and Rb remained hyperphosphorylated despite elevated levels of p16. Instead, RAS promoted anchorage-independent growth of normal fibroblasts, although expression of hTert with RAS increased colony formation and allowed normal fibroblasts to bypass contact inhibition. To test the hypothesis that p16 levels determine how cells respond to RAS, we expressed RAS in freshly isolated fibroblasts that expressed very low levels of p16, in hTert-immortalized fibroblasts that had accumulated intermediate levels of p16, and in IMR90 fibroblasts with high levels of p16. RAS induced growth arrest in cells with higher p16 levels, and this effect was reversed by p16 knockdown in the hTert-immortalized fibroblasts. These findings indicate that culture-imposed stress sensitizes cells to RAS-induced arrest, whereas early passage cells do not arrest in response to RAS. PMID:15024073

Review and Outcome of Prolonged Cardiopulmonary Resuscitation

PubMed Central

Youness, Houssein; Al Halabi, Tarek; Hussein, Hussein; Awab, Ahmed; Jones, Kellie; Keddissi, Jean

2016-01-01

The maximal duration of cardiopulmonary resuscitation (CPR) is unknown. We report a case of prolonged CPR. We have then reviewed all published cases with CPR duration equal to or more than 20 minutes. The objective was to determine the survival rate, the neurological outcome, and the characteristics of the survivors. Measurements and Main Results. The CPR data for 82 patients was reviewed. The median duration of CPR was 75 minutes. Patients mean age was 43 ± 21 years with no significant comorbidities. The main causes of the cardiac arrests were myocardial infarction (29%), hypothermia (21%), and pulmonary emboli (12%). 74% of the arrests were witnessed, with a mean latency to CPR of 2 ± 6 minutes and good quality chest compression provided in 96% of the cases. Adjunct therapy included extracorporeal membrane oxygenation (18%), thrombolysis (15.8%), and rewarming for hypothermia (19.5%). 83% were alive at 1 year, with full neurological recovery reported in 63 patients. Conclusion. Patients undergoing prolonged CPR can survive with good outcome. Young age, myocardial infarction, and potentially reversible causes of cardiac arrest such as hypothermia and pulmonary emboli predict a favorable result, especially when the arrest is witnessed and followed by prompt and good resuscitative efforts. PMID:26885387

Enforcement following 0.08% BAC law change: Sex-specific consequences of changing arrest practices?

PubMed Central

Schwartz, Jennifer; Davaran, Ardavan

2013-01-01

This research evaluated effects of stricter 0.08% BAC drunken driving law on changes in sex-specific DUI arrest rates, controlling for increased law enforcement resources and shifts in DUI-related behaviors. Another main purpose, the study assessed female/male differences in arrest increases due to broader enforcement standards and efforts. Panel data was assembled for 24 states over 1990–2007 on DUI arrests, alcohol policy, law enforcement resources, drinking and drunken driving prevalence. Two-way fixed-effects seemingly unrelated regression models predicted female versus male changes in DUI arrests following implementation of lower legal limits of intoxication, net controls. Findings suggest, first, a broader legal definition of drunken driving intending to officially sanction less serious offenders (0.08% vs. 0.10% BAC) was associated with increased DUI arrests for both sexes. Second, growth in specialized DUI-enforcement units also was related to increased arrests. Whereas male and female arrest trends were equally affected by the direct net-widening effects of 0.08% BAC alcohol-policy, specialized DUI-enforcement efforts to dig deeper into the offender-pool had stronger arrest-producing effects on females, particularly prior to law change. Specifying how changes in law and enforcement resources affect arrest outcomes is an important precursor to alcohol-policy analyses of effectiveness. A potential unintended consequence, effects of law and enforcement may differ across population segments. PMID:23773958

Regenerative Endodontic Treatment of an Immature Necrotic Molar with Arrested Root Development by Using Recombinant Human Platelet-derived Growth Factor: A Case Report.

PubMed

Zhujiang, Annie; Kim, Sahng G

2016-01-01

Regenerative endodontic treatment has provided a treatment option that aims to allow root maturation. The present report describes the regenerative endodontic treatment of a necrotic, immature molar by using recombinant human platelet-derived growth factor (rhPDGF-BB) and shows the continued root maturation in the tooth with arrested root development. A regenerative endodontic procedure that used a growth factor was performed for a necrotic molar with arrested root formation in a 20-year-old patient. Thorough disinfection by using mechanical instrumentation and copious irrigation of antimicrobial agents as well as intracanal medication with calcium hydroxide was performed throughout the first 2 appointments. At the third appointment, the root canals were irrigated with an antimicrobial solution and 17% EDTA, and bleeding was evoked by passing sterile paper points beyond the apex in each canal. Small pieces of a collagen membrane saturated with rhPDGF-BB solution from GEM 21S were packed into each canal. Mineral trioxide aggregate was placed, and Cavit and composite resin were used to restore the tooth. Complete root maturation and resolution of a periapical radiolucency were observed at the 15-month follow-up. The present report presents a regenerative endodontic procedure that uses rhPDGF-BB for a necrotic molar with arrested root development. The finding of continued root development in the present case suggests that regenerative endodontic treatment may be able to resume the root maturation process in teeth with arrested root formation. Further clinical studies are required to investigate the efficacy of rhPDGF-BB in regenerative endodontic treatment. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Theileria parva infection induces autocrine growth of bovine lymphocytes.

PubMed Central

Dobbelaere, D A; Coquerelle, T M; Roditi, I J; Eichhorn, M; Williams, R O

1988-01-01

Bovine lymphocytes infected with the parasite Theileria parva continuously secrete a growth factor that is essential for their proliferation in vitro and also constitutively express interleukin 2 receptors on their surface. Dilution of the secreted growth factor, caused by culturing cells at low density, results in retardation of culture growth. Human recombinant interleukin 2, however, effectively substitutes for the diluted growth factor by restoring normal growth rates and also allows Theileria-infected cells to be grown at low density without the use of feeder layers. Secretion of the growth factor and expression of the interleukin 2 receptor depend on the presence of the parasite in the cytoplasm of the host cell. Elimination of the parasite from the cell cytoplasm by the specific antitheilerial drug BW 720c results in the arrest of growth factor secretion and the disappearance of interleukin 2 receptors from the cell surface. This is accompanied by growth arrest and reversion of the infected cells to the morphology of resting lymphocytes. We propose that the continuous proliferation of infected cells in vitro is mediated by autocrine receptor activation. Images PMID:3133661

Xanthorrhizol, a natural sesquiterpenoid, induces apoptosis and growth arrest in HCT116 human colon cancer cells.

PubMed

Kang, You-Jin; Park, Kwang-Kyun; Chung, Won-Yoon; Hwang, Jae-Kwan; Lee, Sang Kook

2009-11-01

Xanthorrhizol is a sesquiterpenoid from the rhizome of Curcuma xanthorrhiza. In our previous studies, xanthorrhizol suppressed cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, inhibited cancer cell growth, and exerted an anti-metastatic effect in an animal model. However, the exact mechanisms for its inhibitory effects against cancer cell growth have not yet been fully elucidated. In the present study, we investigated the growth inhibitory effect of xanthorrhizol on cancer cells. Xanthorrhizol dose-dependently exerted antiproliferative effects against HCT116 human colon cancer cells. Xanthorrhizol also arrested cell cycle progression in the G0/G1 and G2/M phase and induced the increase of sub-G1 peaks. Cell cycle arrest was highly correlated with the downregulation of cyclin A, cyclin B1, and cyclin D1; cyclin-dependent kinase 1 (CDK1), CDK2, and CDK4; proliferating cell nuclear antigen; and inductions of p21 and p27, cyclin-dependent kinase inhibitors. The apoptosis by xanthorrhizol was markedly evidenced by induction of DNA fragmentation, release of cytochrome c, activation of caspases, and cleavage of poly-(ADP-ribose) polymerase. In addition, xanthorrhizol increased the expression and promoter activity of pro-apoptotic non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). These findings provide one plausible mechanism for the growth inhibitory activity of xanthorrhizol against cancer cells.

Hyperspectral near infrared spectroscopy assessment of the brain during hypoperfusion

NASA Astrophysics Data System (ADS)

Nguyen, Thu N.; Wu, Wen; Woldemichael, Ermias; Toronov, Vladislav; Lin, Steve

2018-02-01

Two-thirds of out-of-hospital cardiac arrest patients, who survive to hospital admission, die in the hospital from neurological injuries related to cerebral hypoperfusion. Hyperspectral near infrared spectroscopy (hNIRS) is a noninvasive technique that measures the major chromophores in the brain, such as oxygenated hemoglobin, deoxygenated hemoglobin and cytochrome C oxidase ([CCO]), an intracellular marker of oxygen consumption. We have demonstrated that hNIRS is feasible and can detect changes in cerebral oxygenation and metabolism in patients undergoing transcatheter aortic valve insertion (TAVI) - a procedure that temporarily induces sudden hypotension and hypoperfusion that mimics cardiac arrest. Using multi-distance hNIRS, we found that while measured regional oxygen saturation (rSO2) changes resulted mainly from the extra-cerebral tissues, [CCO] changes during cardiac arrests occurred mainly in the brains of patients. We also applied the hNIRS algorithm based on the "2-layer model" to the data to measure cerebral oxygen saturation and [CCO] in patients during the procedure.

Spliceosomal protein E regulates neoplastic cell growth by modulating expression of cyclin E/CDK2 and G2/M checkpoint proteins.

PubMed

Li, Z; Pützer, B M

2008-12-01

Small nuclear ribonucleoproteins are essential splicing factors. We previously identified the spliceosomal protein E (SmE) as a downstream effector of E2F1 in p53-deficient human carcinoma cells. Here, we investigated the biological relevance of SmE in determining the fate of cancer and non-tumourigenic cells. Adenovirus-mediated expression of SmE selectively reduces growth of cancerous cells due to decreased cell proliferation but not apoptosis. A similar growth inhibitory effect for SmD1 suggests that this is a general function of Sm-family members. Deletion of Sm-motifs reveals the importance of the Sm-1 domain for growth suppression. Consistently, SmE overexpression leads to inhibition of DNA synthesis and G2 arrest as shown by BrdU-incorporation and MPM2-staining. Real-time RT-PCR and immunoblotting showed that growth arrest by SmE directly correlates with the reduction of cyclin E, CDK2, CDC25C and CDC2 expression, and up-regulation of p27Kip. Importantly, SmE activity was not associated with enhanced expression of other spliceosome components such as U1 SnRNP70, suggesting that the growth inhibitory effect of SmE is distinct from its pre-mRNA splicing function. Furthermore, specific inactivation of SmE by shRNA significantly increased the percentage of cells in S phase, whereas the amount of G2/M arrested cells was reduced. Our data provide evidence that Sm proteins function as suppressors of tumour cell growth and may have major implications as cancer therapeutics.

A Role for Fibroblasts in Mediating the Effects of Tobacco-Induced Epithelial Cell Growth and Invasion

PubMed Central

Coppe, Jean-Philippe; Boysen, Megan; Ho Sun, Chung; Wong, Brian J.F.; Kang, Mo K.; Park, No-Hee; Desprez, Pierre-Yves; Campisi, Judith; Krtolica, Ana

2009-01-01

Cigarette smoke and smokeless tobacco extracts contain multiple carcinogenic compounds, but little is known about the mechanisms by which tumors develop and progress upon chronic exposure to carcinogens such as those present in tobacco products. Here, we examine the effects of smokeless tobacco extracts on human oral fibroblasts. We show that smokeless tobacco extracts elevated the levels of intracellular reactive oxygen, oxidative DNA damage, and DNA double-strand breaks in a dose-dependent manner. Extended exposure to extracts induced fibroblasts to undergo a senescence-like growth arrest, with striking accompanying changes in the secretory phenotype. Using cocultures of smokeless tobacco extracts–exposed fibroblasts and immortalized but nontumorigenic keratinocytes, we further show that factors secreted by extracts-modified fibroblasts increase the proliferation and invasiveness of partially transformed epithelial cells, but not their normal counterparts. In addition, smokeless tobacco extracts–exposed fibroblasts caused partially transformed keratinocytes to lose the expression of E-cadherin and ZO-1, as well as involucrin, changes that are indicative of compromised epithelial function and commonly associated with malignant progression. Together, our results suggest that fibroblasts may contribute to tumorigenesis indirectly by increasing epithelial cell aggressiveness. Thus, tobacco may not only initiate mutagenic changes in epithelial cells but also promote the growth and invasion of mutant cells by creating a procarcinogenic stromal environment. PMID:18644973

Rapamycin causes growth arrest and inhibition of invasion in human chondrosarcoma cells.

PubMed

Song, Jian; Wang, Xiaobo; Zhu, Jiaxue; Liu, Jun

2016-01-01

Chondrosarcoma is a highly malignant tumor that is characterized by a potent capacity to invade locally and cause distant metastasis and notable for its lack of response to conventional chemotherapy or radiotherapy. Rapamycin, the inhibitor of mammalian target of rapamycin (mTOR), is a valuable drug with diverse clinical applications and regulates many cellular processes. However, the effects of rapamycin on cell growth and invasion of human chondrosarcoma cells are not well known. We determined the effect of rapamycin on cell proliferation, cell cycle arrest and invasion by using MTS, flow cytometry and invasion assays in two human chondrosarcoma cell lines, SW1353 and JJ012. Cell cycle regulatory and invasion-related genes' expression analysis was performed by quantitative RT-PCR (qRT-PCR). We also evaluated the effect of rapamycin on tumor growth by using mice xenograph models. Rapamycin significantly inhibited the cell proliferation, induced cell cycle arrest and decreased the invasion ability of human chondrosarcoma cells. Meanwhile, rapamycin modulated the cell cycle regulatory and invasion-related genes' expression. Furthermore, the tumor growth of mice xenograph models with human chondrosarcoma cells was significantly inhibited by rapamycin. These results provided further insight into the role of rapamycin in chondrosarcoma. Therefore, rapamycin targeted therapy may be a potential treatment strategy for chondrosarcoma.

RRR-alpha-tocopheryl succinate inhibits EL4 thymic lymphoma cell growth by inducing apoptosis and DNA synthesis arrest.

PubMed

Yu, W; Sanders, B G; Kline, K

1997-01-01

RRR-alpha-tocopheryl succinate (vitamin E succinate, VES) treatment of murine EL4 T lymphoma cells induced the cells to undergo apoptosis. After 48 hours of VES treatment at 20 micrograms/ml, 95% of cells were apoptotic. Evidence for the induction of apoptosis by VES treatments is based on staining of DNA for detection of chromatin condensation/fragmentation, two-color flow-cytometric analyses of DNA content, and end-labeled DNA and electrophoretic analyses for detection of DNA ladder formation. VES-treated EL4 cells were blocked in the G1 cell cycle phase; however, apoptotic cells came from all cell cycle phases. Analyses of mRNA expression of genes involved in apoptosis revealed decreased c-myc and increased bcl-2, c-fos, and c-jun mRNAs within three to six hours after treatment. Western analyses showed increased c-Jun, c-Fos, and Bcl-2 protein levels. Electrophoretic mobility shift assays showed increased AP-1 binding at 6, 12, and 24 hours after treatment and decreased c-Myc binding after 12 and 24 hours of VES treatment. Treatments of EL4 cells with VES+RRR-alpha-to-copherol reduced apoptosis without effecting DNA synthesis arrest. Treatments of EL4 cells with VES+rac-6-hydroxyl-2, 5,7,8-tetramethyl-chroman-2-carboxylic acid, butylated hydroxytoluene, or butylated hydroxyanisole had no effect on apoptosis or DNA synthesis arrest caused by VES treatments. Analyses of bcl-2, c-myc, c-jun, and c-fos mRNA levels in cells receiving VES + RRR-alpha-tocopherol treatments showed no change from cells receiving VES treatments alone, implying that these changes are correlated with VES treatments but are not causal for apoptosis. However, treatments with VES + RRR-alpha-tocopherol decreased AP-1 binding to consensus DNA oligomer, suggesting AP-1 involvement in apoptosis induced by VES treatments.

Heat shock factor-1 intertwines insulin/IGF-1, TGF-β and cGMP signaling to control development and aging.

PubMed

Barna, János; Princz, Andrea; Kosztelnik, Mónika; Hargitai, Balázs; Takács-Vellai, Krisztina; Vellai, Tibor

2012-11-01

Temperature affects virtually all cellular processes. A quick increase in temperature challenges the cells to undergo a heat shock response to maintain cellular homeostasis. Heat shock factor-1 (HSF-1) functions as a major player in this response as it activates the transcription of genes coding for molecular chaperones (also called heat shock proteins) that maintain structural integrity of proteins. However, the mechanisms by which HSF-1 adjusts fundamental cellular processes such as growth, proliferation, differentiation and aging to the ambient temperature remain largely unknown. We demonstrate here that in Caenorhabditis elegans HSF-1 represses the expression of daf-7 encoding a TGF-β (transforming growth factor-beta) ligand, to induce young larvae to enter the dauer stage, a developmentally arrested, non-feeding, highly stress-resistant, long-lived larval form triggered by crowding and starvation. Under favorable conditions, HSF-1 is inhibited by crowding pheromone-sensitive guanylate cyclase/cGMP (cyclic guanosine monophosphate) and systemic nutrient-sensing insulin/IGF-1 (insulin-like growth factor-1) signaling; loss of HSF-1 activity allows DAF-7 to promote reproductive growth. Thus, HSF-1 interconnects the insulin/IGF-1, TGF-β and cGMP neuroendocrine systems to control development and longevity in response to diverse environmental stimuli. Furthermore, HSF-1 upregulates another TGF-β pathway-interacting gene, daf-9/cytochrome P450, thereby fine-tuning the decision between normal growth and dauer formation. Together, these results provide mechanistic insight into how temperature, nutrient availability and population density coordinately influence development, lifespan, behavior and stress response through HSF-1.

Management of Patients with Cardiac Arrest Complicating Myocardial Infarction in New York Before and After Public Reporting Policy Changes

PubMed Central

Strom, Jordan B.; McCabe, James M.; Waldo, Stephen W.; Pinto, Duane; Kennedy, Kevin F.; Feldman, Dmitriy N.; Yeh, Robert W.

2017-01-01

Background In 2010, New York State began excluding selected patients with cardiac arrest and coma from publicly reported mortality statistics after percutaneous coronary intervention (PCI). We evaluated the effects of this exclusion on rates of coronary angiography, revascularization, and mortality among patients with acute myocardial infarction (AMI) and cardiac arrest. Methods and Results Using statewide hospitalization files, we identified discharges for AMI and cardiac arrest 1/2003–12/2013 in New York and several comparator states. A difference-in-differences approach was used to evaluate the likelihood of coronary angiography, revascularization, and in-hospital mortality before and after 2010. A total of 26,379 patients with AMI and cardiac arrest (5,619 in New York) were included. Of these, 17,141 (65%) underwent coronary angiography, 12,183 (46.2%) underwent PCI and 2,832 (10.7%) underwent CABG. Prior to 2010, cardiac arrest patients in New York were less likely to undergo PCI compared with referent states (aRR 0.79, 95% CI 0,73–0.85, p<0.001). This relationship was unchanged after the policy change (aRR 0.82, 95% CI 0.76–0.89, interaction p = 0.359). Adjusted risks of in-hospital mortality between New York and comparator states after 2010 were also similar (aRR 0.94, 95% CI 0.87–1.02, p = 0.152 for post- vs. pre-2010 in New York, aRR 0.88, 95% CI 0.84–0.92, p <0.001 for comparator states; interaction p = 0.103). Conclusions Exclusion of selected cardiac arrest cases from public reporting was not associated with changes in rates of PCI or in-hospital mortality in New York. Rates of revascularization in New York for cardiac arrest patients were lower throughout. PMID:28495895

Management of Patients With Cardiac Arrest Complicating Myocardial Infarction in New York Before and After Public Reporting Policy Changes.

PubMed

Strom, Jordan B; McCabe, James M; Waldo, Stephen W; Pinto, Duane S; Kennedy, Kevin F; Feldman, Dmitriy N; Yeh, Robert W

2017-05-01

In 2010, New York State began excluding selected patients with cardiac arrest and coma from publicly reported mortality statistics after percutaneous coronary intervention. We evaluated the effects of this exclusion on rates of coronary angiography, revascularization, and mortality among patients with acute myocardial infarction and cardiac arrest. Using statewide hospitalization files, we identified discharges for acute myocardial infarction and cardiac arrest January 2003 to December 2013 in New York and several comparator states. A difference-in-differences approach was used to evaluate the likelihood of coronary angiography, revascularization, and in-hospital mortality before and after 2010. A total of 26 379 patients with acute myocardial infarction and cardiac arrest (5619 in New York) were included. Of these, 17 141 (65%) underwent coronary angiography, 12 183 (46.2%) underwent percutaneous coronary intervention, and 2832 (10.7%) underwent coronary artery bypass grafting. Before 2010, patients with cardiac arrest in New York were less likely to undergo percutaneous coronary intervention compared with referent states (adjusted relative risk, 0.79; 95% confidence interval, 0.73-0.85; P <0.001). This relationship was unchanged after the policy change (adjusted relative risk, 0.82; 95% confidence interval, 0.76-0.89; interaction P =0.359). Adjusted risks of in-hospital mortality between New York and comparator states after 2010 were also similar (adjusted relative risk, 0.94; 95% confidence interval, 0.87-1.02; P =0.152 for post- versus pre-2010 in New York; adjusted relative risk, 0.88; 95% confidence interval, 0.84-0.92; P <0.001 for comparator states; interaction P =0.103). Exclusion of selected cardiac arrest cases from public reporting was not associated with changes in rates of percutaneous coronary intervention or in-hospital mortality in New York. Rates of revascularization in New York for cardiac arrest patients were lower throughout. © 2017 American Heart Association, Inc.

Formation of solid tumors by a single multinucleated cancer cel

PubMed Central

Weihua, Zhang; Lin, Qingtang; Ramoth, Asa J.; Fan, Dominic; Fidler, Isaiah J.

2011-01-01

BACKGROUND Large multinucleated cells (MNC) commonly exist in tumorigenic cancer cell lines widely used in research, but their contributions to tumorigenesis are unknown. METHODS In this study, we characterized MNCs in the murine fibrosarcoma cell line UV-2237 in vitro and in vivo at a single cell level. RESULTS We observed that MNCs originated from a rare subpopulation of mononuclear cells; MNCs were positive for a senescent marker, β-galacosidase (SA-β-Gal); MNCs were responsible for the majority of clonogenic activity when cultured in hard agar; MNCs were more resistant to chemotherapeutic agents than were mononuclear cells; MNCs could undergo asymmetric division (producing mononuclear cells) and self-renewal in vitro and in vivo; and, most importantly a single MNC produced orthotopic subcutaneous tumors (composed mainly of mononuclear cells) that gave rise to spontaneous lung metastases in nude mice. CONCLUSIONS MNCs can be growth-arrested under stress, are highly resistant to chemotherapy, and can generate clonal orthotopic metastatic tumors PMID:21365635

The suture provides a niche for mesenchymal stem cells of craniofacial bones

PubMed Central

Zhao, Hu; Feng, Jifan; Ho, Thach-Vu; Grimes, Weston; Urata, Mark; Chai, Yang

2015-01-01

Bone tissue undergoes constant turnover supported by stem cells. Recent studies showed that perivascular mesenchymal stem cells (MSCs) contribute to the turnover of long bones. Craniofacial bones are flat bones derived from a different embryonic origin than the long bones. The identity and regulating niche for craniofacial bone MSCs remain unknown. Here, we identify Gli1+ cells within the suture mesenchyme as the major MSC population for craniofacial bones. They are not associated with vasculature, give rise to all craniofacial bones in the adult and are activated during injury repair. Gli1+ cells are typical MSCs in vitro. Ablation of Gli1+ cells leads to craniosynostosis and arrest of skull growth, indicating these cells are an indispensible stem cell population. Twist1+/− mice with craniosynostosis show reduced Gli1+ MSCs in sutures, suggesting that craniosynostosis may result from diminished suture stem cells. Our study indicates that craniofacial sutures provide a unique niche for MSCs for craniofacial bone homeostasis and repair. PMID:25799059

Inhibition of l-type amino acid transporter 1 activity as a new therapeutic target for cholangiocarcinoma treatment.

PubMed

Yothaisong, Supak; Dokduang, Hasaya; Anzai, Naohiko; Hayashi, Keitaro; Namwat, Nisana; Yongvanit, Puangrat; Sangkhamanon, Sakkarn; Jutabha, Promsuk; Endou, Hitoshi; Loilome, Watcharin

2017-03-01

Unlike normal cells, cancer cells undergo unlimited growth and multiplication, causing them to require massive amounts of amino acid to support their continuous metabolism. Among the amino acid transporters expressed on the plasma membrane, l-type amino acid transporter-1, a Na + -independent neutral amino acid transporter, is highly expressed in many types of human cancer including cholangiocarcinoma. Our previous study reported that l-type amino acid transporter-1 and its co-functional protein CD98 were highly expressed and implicated in cholangiocarcinoma progression and carcinogenesis. Therefore, this study determined the effect of JPH203, a selective inhibitor of l-type amino acid transporter-1 activity, on cholangiocarcinoma cell inhibition both in vitro and in vivo. JPH203 dramatically suppressed [ 14 C]l-leucine uptake as well as cell growth in cholangiocarcinoma cell lines along with altering the expression of l-type amino acid transporter-1 and CD98 in response to amino acid depletion. We also demonstrated that JPH203 induced both G2/M and G0/G1 cell cycle arrest, as well as reduced the S phase accompanied by altered expression of the proteins in cell cycle progression: cyclin D1, CDK4, and CDK6. There was also cell cycle arrest of the related proteins, P21 and P27, in KKU-055 and KKU-213 cholangiocarcinoma cells. Apoptosis induction, detected by an increase in trypan blue-stained cells along with a cleaved caspase-3/caspase-3 ratio, occurred in JPH203-treated cholangiocarcinoma cells at the highest concentration tested (100 µM). As expected, daily intravenous administration of JPH203 (12.5 and 25 mg/kg) significantly inhibited tumor growth in KKU-213 cholangiocarcinoma cell xenografts in the nude mice model in a dose-dependent manner with no statistically significant change in the animal's body weight and with no differences in the histology and appearance of the internal organs compared with the control group. Our study demonstrates that suppression of l-type amino acid transporter-1 activity using JPH203 might be used as a new therapeutic strategy for cholangiocarcinoma treatment.

Effects of benzalkonium chloride on growth and survival of Chang conjunctival cells.

PubMed

De Saint Jean, M; Brignole, F; Bringuier, A F; Bauchet, A; Feldmann, G; Baudouin, C

1999-03-01

The aim of this study was to investigate the action of benzalkonium chloride (BAC), used as a preservative in most ophthalmic topical solutions, on epithelial conjunctival cells in vitro. A continuous human conjunctival cell line (Wong-Kilbourne derivative of Chang conjunctiva) was exposed to BAC solutions at various concentrations (0.1%-0.0001%) during a period of 10 minutes. Cells were examined before treatment and 3, 24, 48, and 72 hours later, after reexposure to normal cell culture conditions. Cell number and viability were assessed with crystal violet and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide colorimetric assays. The expression of the apoptotic marker Apo 2.7, nuclear antigen p53, membrane proteins Fas and Fas ligand, and DNA content was studied by flow cytometry. Morphologic aspects of cell nuclei were analyzed on slides with a nucleic acid-specific dye, 4',6'-diamidino-2-phenylindole dihydrochloride. Cytoskeleton was labeled with a monoclonal anti-pancytokeratin antibody. In addition, apoptosis was measured by DNA electrophoresis assays in agarose gel. Cell exposure to 0.1% and 0.05% BAC induced cell lysis immediately after treatment. All cells (100%) treated with 0.01% BAC died in a delayed manner within 24 hours, with most of the characteristics of apoptosis (chromatin condensation and DNA fragmentation, reduction in cell volume, expression of the apoptotic marker Apo 2.7, and apoptotic changes in DNA content). Aliquots of 0.005%, 0.001%, 0.0005%, and 0.0001% BAC induced growth arrest and apoptotic cell death in a dose-dependent manner between 24 and 72 hours after treatment. The expressions of Fas and p53 did not vary after BAC treatment. Fas ligand was always negative. These results suggest that BAC induces cell growth arrest and death at a concentration as low as 0.0001%. The mode of BAC-induced cell death is dose-dependent. Cells die by necrosis after BAC treatment at high concentrations and by apoptosis if low concentrations of BAC are applied. This new aspect of in vitro toxicity of BAC could in part explain some ocular surface disorders observed in patients undergoing long-term topical treatments with preservative-containing drugs.

New Indole Tubulin Assembly Inhibitors Cause Stable Arrest of Mitotic Progression, Enhanced Stimulation of Natural Killer Cell Cytotoxic Activity, and Repression of Hedgehog-Dependent Cancer.

PubMed

La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Verrico, Annalisa; Miele, Andrea; Monti, Ludovica; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Ricci, Biancamaria; Soriani, Alessandra; Santoni, Angela; Caraglia, Michele; Porto, Stefania; Da Pozzo, Eleonora; Martini, Claudia; Brancale, Andrea; Marinelli, Luciana; Novellino, Ettore; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Bigogno, Chiara; Dondio, Giulio; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

2015-08-13

We designed 39 new 2-phenylindole derivatives as potential anticancer agents bearing the 3,4,5-trimethoxyphenyl moiety with a sulfur, ketone, or methylene bridging group at position 3 of the indole and with halogen or methoxy substituent(s) at positions 4-7. Compounds 33 and 44 strongly inhibited the growth of the P-glycoprotein-overexpressing multi-drug-resistant cell lines NCI/ADR-RES and Messa/Dx5. At 10 nM, 33 and 44 stimulated the cytotoxic activity of NK cells. At 20-50 nM, 33 and 44 arrested >80% of HeLa cells in the G2/M phase of the cell cycle, with stable arrest of mitotic progression. Cell cycle arrest was followed by cell death. Indoles 33, 44, and 81 showed strong inhibition of the SAG-induced Hedgehog signaling activation in NIH3T3 Shh-Light II cells with IC50 values of 19, 72, and 38 nM, respectively. Compounds of this class potently inhibited tubulin polymerization and cancer cell growth, including stimulation of natural killer cell cytotoxic activity and repression of Hedgehog-dependent cancer.

New Indole Tubulin Assembly Inhibitors Cause Stable Arrest of Mitotic Progression, Enhanced Stimulation of Natural Killer Cell Cytotoxic Activity, and Repression of Hedgehog-Dependent Cancer

PubMed Central

La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Verrico, Annalisa; Miele, Andrea; Monti, Ludovica; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Ricci, Biancamaria; Soriani, Alessandra; Santoni, Angela; Caraglia, Michele; Porto, Stefania; Pozzo, Eleonora Da; Martini, Claudia; Brancale, Andrea; Marinelli, Luciana; Novellino, Ettore; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Bigogno, Chiara; Dondio, Giulio; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

2015-01-01

We designed 39 new 2-phenylindole derivatives as potential anticancer agents bearing the 3,4,5-trimethox-yphenyl moiety with a sulfur, ketone, or methylene bridging group at position 3 of the indole and with halogen or methoxy substituent(s) at positions 4–7. Compounds 33 and 44 strongly inhibited the growth of the P-glycoprotein-overexpressing multi-drug-resistant cell lines NCI/ADR-RES and Messa/Dx5. At 10 nM, 33 and 44 stimulated the cytotoxic activity of NK cells. At 20–50 nM, 33 and 44 arrested >80% of HeLa cells in the G2/M phase of the cell cycle, with stable arrest of mitotic progression. Cell cycle arrest was followed by cell death. Indoles 33, 44, and 81 showed strong inhibition of the SAG-induced Hedgehog signaling activation in NIH3T3 Shh-Light II cells with IC50 values of 19, 72, and 38 nM, respectively. Compounds of this class potently inhibited tubulin polymerization and cancer cell growth, including stimulation of natural killer cell cytotoxic activity and repression of Hedgehog-dependent cancer. PMID:26132075

Calcium influences sensitivity to growth inhibition induced by a cell surface sialoglycopeptide

NASA Technical Reports Server (NTRS)

Betz, N. A.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

1994-01-01

While studies concerning mitogenic factors have been an important area of research for many years, much less is understood about the mechanisms of action of cell surface growth inhibitors. We have purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) which can reversibly inhibit the proliferation of diverse cell types. The studies discussed in this article show that three mouse keratinocyte cell lines exhibit sixty-fold greater sensitivity than other fibroblasts and epithelial-like cells to CeReS-18-induced growth inhibition. Growth inhibition induced by CeReS-18 treatment is a reversible process, and the three mouse keratinocyte cell lines exhibited either single or multiple cell cycle arrest points, although a predominantly G0/G1 cell cycle arrest point was exhibited in Swiss 3T3 fibroblasts. The sensitivity of the mouse keratinocyte cell lines to CeReS-18-induced growth inhibition was not affected by the degree of tumorigenic progression in the cell lines and was not due to differences in CeReS-18 binding affinity or number of cell surface receptors per cell. However, the sensitivity of both murine fibroblasts and keratinocytes could be altered by changing the extracellular calcium concentration, such that increased extracellular calcium concentrations resulted in decreased sensitivity to CeReS-18-induced proliferation inhibition. Thus the increased sensitivity of the murine keratinocyte cell lines to CeReS-18 could be ascribed to the low calcium concentration used in their propagation. Studies are currently under way investigating the role of calcium in CeReS-18-induced growth arrest. The CeReS-18 may serve as a very useful tool to study negative growth control and the signal transduction events associated with cell cycling.

Activation of GPR30 inhibits growth of prostate cancer cells via sustained activation of Erk1/2, c-jun/c-fos-dependent upregulation of p21, and induction of G2 cell-cycle arrest

PubMed Central

Chan, Queeny K.Y.; Lam, Hung-Ming; Ng, Chi-Fai; Lee, Amy Y.Y.; Chan, Eddie S.Y.; Ng, Ho-Keung; Ho, Shuk-Mei; Lau, Kin-Mang

2010-01-01

G protein–coupled receptor 30 (GPR30) exhibits estrogen-binding affinity and mediates nongenomic signaling of estrogen to regulate cell growth. We here demonstrated for the first time, in contrast to the reported promoting action of GPR30 on the growth of breast and ovarian cancer cells, that activation of GPR30 by the receptor-specific, non-estrogenic ligand G-1 inhibited growth of androgen-dependent and -independent prostate cancer (PCa) cells in vitro and PC-3 xenografts in vivo. However, G-1 elicited no growth or histological changes in the prostates of intact mice and did not inhibit growth in quiescent BPH-1, an immortalized benign prostatic epithelial cell line. Treatment of PC-3 cells with G-1-induced cell-cycle arrest at the G2 phase and reduced the expression of G2-checkpoint regulators (cyclin A2, cyclin B1, cdc25c, and cdc2) and the phosphorylation of their common transcriptional regulator NF-YA in PC-3 cells. With the extensive use of siRNA knockdown experiments and the MEK inhibitor PD98059 in the present study, we dissected the mechanism underlying G-1–induced inhibition of PC-3 cell growth, which was mediated through GPR30, followed by a sustained activation of Erk1/2 and a c-jun/c-fos-dependent upregulation of p21, resulting in the arrest of PC-3 growth at the G2 phase. The discovery of this signaling pathway lays the foundation for future development of GPR30-based therapies for PCa. PMID:20203690

Identification of Late Larval Stage Developmental Checkpoints in Caenorhabditis elegans Regulated by Insulin/IGF and Steroid Hormone Signaling Pathways

PubMed Central

Schindler, Adam J.; Baugh, L. Ryan; Sherwood, David R.

2014-01-01

Organisms in the wild develop with varying food availability. During periods of nutritional scarcity, development may slow or arrest until conditions improve. The ability to modulate developmental programs in response to poor nutritional conditions requires a means of sensing the changing nutritional environment and limiting tissue growth. The mechanisms by which organisms accomplish this adaptation are not well understood. We sought to study this question by examining the effects of nutrient deprivation on Caenorhabditis elegans development during the late larval stages, L3 and L4, a period of extensive tissue growth and morphogenesis. By removing animals from food at different times, we show here that specific checkpoints exist in the early L3 and early L4 stages that systemically arrest the development of diverse tissues and cellular processes. These checkpoints occur once in each larval stage after molting and prior to initiation of the subsequent molting cycle. DAF-2, the insulin/insulin-like growth factor receptor, regulates passage through the L3 and L4 checkpoints in response to nutrition. The FOXO transcription factor DAF-16, a major target of insulin-like signaling, functions cell-nonautonomously in the hypodermis (skin) to arrest developmental upon nutrient removal. The effects of DAF-16 on progression through the L3 and L4 stages are mediated by DAF-9, a cytochrome P450 ortholog involved in the production of C. elegans steroid hormones. Our results identify a novel mode of C. elegans growth in which development progresses from one checkpoint to the next. At each checkpoint, nutritional conditions determine whether animals remain arrested or continue development to the next checkpoint. PMID:24945623

Enforcement following 0.08% BAC law change: sex-specific consequences of changing arrest practices?

PubMed

Schwartz, Jennifer; Davaran, Ardavan

2013-10-01

This research evaluated effects of stricter 0.08% BAC drunken driving law on changes in sex-specific DUI arrest rates, controlling for increased law enforcement resources and shifts in DUI-related behaviors. Another main purpose, the study assessed female/male differences in arrest increases due to broader enforcement standards and efforts. Panel data was assembled for 24 states over 1990-2007 on DUI arrests, alcohol policy, law enforcement resources, drinking and drunken driving prevalence. Two-way fixed-effects seemingly unrelated regression models predicted female versus male changes in DUI arrests following implementation of lower legal limits of intoxication, net controls. Findings suggest, first, that a broader legal definition of drunken driving intending to officially sanction less serious offenders (0.08% vs. 0.10% BAC) was associated with increased DUI arrests for both sexes. Second, growth in specialized DUI-enforcement units also was related to increased arrests. Whereas male and female arrest trends were equally affected by the direct net-widening effects of 0.08% BAC alcohol-policy, specialized DUI-enforcement efforts to dig deeper into the offender-pool had stronger arrest-producing effects on females, particularly prior to law change. Specifying how changes in law and enforcement resources affect arrest outcomes is an important pre-cursor to alcohol-policy analyses of effectiveness. A potential unintended consequence, effects of law and enforcement may differ across population segments. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

4-O-Methylhonokiol Protects HaCaT Cells from TGF-β1-Induced Cell Cycle Arrest by Regulating Canonical and Non-Canonical Pathways of TGF-β Signaling.

PubMed

Kim, Sang-Cheol; Kang, Jung-Il; Hyun, Jin-Won; Kang, Ji-Hoon; Koh, Young-Sang; Kim, Young-Heui; Kim, Ki-Ho; Ko, Ji-Hee; Yoo, Eun-Sook; Kang, Hee-Kyoung

2017-07-01

4- O -methylhonokiol, a neolignan compound from Magnolia Officinalis , has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-β (TGF-β) signal pathway has an essential role in the regression induction of hair growth, the effect of 4- O -methylhonokiol on the TGF-β signal pathway has not yet been elucidated. We thus examined the effect of 4- O -methylhonokiol on TGF-β-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4- O -methylhonokiol, TGF-β1-induced G1/G0 phase arrest and TGF-β1-induced p21 expression were decreased. Moreover, 4- O -methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-β1-induced canonical pathway. We observed that ERK phosphorylation by TGF-β1 was significantly attenuated by treatment with 4- O -methylhonokiol. 4- O -methylhonokiol inhibited TGF-β1-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-β1-induced noncanonical pathway. These results indicate that 4- O -methylhonokiol could inhibit TGF-β1-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4- O -methylhonokiol might have protective action on TGF-β1-induced cell cycle arrest.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Haihe; Yang, Zhanchun; Liu, Chunbo

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.more » 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.« less

An unanticipated cardiac arrest and unusual post-resuscitation psycho-behavioural phenomena/near death experience in a patient with pregnancy induced hypertension and twin pregnancy undergoing elective lower segment caesarean section.

PubMed

Panditrao, Mridul M; Singh, Chanchal; Panditrao, Minnu M

2010-09-01

A case report of a primigravida, who was admitted with severe pregnancy induced hypertension (BP 160/122 mmHg) and twin pregnancy, is presented here. Antihypertensive therapy was initiated. Elective LSCS under general anaesthesia was planned. After the birth of both the babies, intramyometrial injections of Carboprost and Pitocin were administered. Immediately, she suffered cardiac arrest. Cardio pulmonary resucitation (CPR) was started and within 3 minutes, she was successfully resuscitated. The patient initially showed peculiar psychological changes and with passage of time, certain psycho-behavioural patterns emerged which could be attributed to near death experiences, as described in this case report.

CM363, a novel naphthoquinone derivative which acts as multikinase modulator and overcomes imatinib resistance in chronic myelogenous leukemia

PubMed Central

Díaz-Chico, Juan Carlos; McNaughton-Smith, Grant; Jiménez-Alonso, Sandra; Hueso-Falcón, Idaira; Montero, Juan Carlos; Blanco, Raquel; León, Javier; Rodríguez-González, Germán; Estévez-Braun, Ana; Pandiella, Atanasio; Díaz-Chico, Bonifacio Nicolás; Fernández-Pérez, Leandro

2017-01-01

Human Chronic Myelogenous Leukemia (CML) is a hematological stem cell disorder which is associated with activation of Bcr-Abl-Stat5 oncogenic pathway. Direct Bcr-Abl inhibitors are initially successful for the treatment of CML but over time many patients develop drug resistance. In the present study, the effects of CM363, a novel naphthoquinone (NPQ) derivative, were evaluated on human CML-derived K562 cells. CM363 revealed an effective cell growth inhibition (IC50 = 0.7 ± 0.5 μM) by inducing cancer cells to undergo cell cycle arrest and apoptosis. CM363 caused a dose- and time-dependent reduction of cells in G0/G1 and G2/M phases. This cell cycle arrest was associated with increased levels of cyclin E, pChk1 and pChk2 whereas CM363 downregulated cyclin B, cyclin D3, p27, pRB, Wee1, and BUBR1. CM363 increased the double-strand DNA break marker γH2AX. CM363 caused a time-dependent increase of annexin V-positive cells, DNA fragmentation and increased number of apoptotic nuclei. CM363 triggered the mitochondrial apoptotic pathway as reflected by a release of cytochrome C from mitochondria and induction of the cleavage of caspase-3 and -9, and PARP. CM363 showed multikinase modulatory effects through an early increased JNK phosphorylation followed by inhibition of pY-Bcrl-Abl and pY-Stat5. CM363 worked synergistically with imatinib to inhibit cell viability and maintained its activity in imatinib-resistant cells. Finally, CM363 (10 mg/Kg) suppressed the growth of K562 xenograft tumors in athymic mice. In summary, CM363 is a novel multikinase modulator that offers advantages to circumvent imanitib resistance and might be therapeutically effective in Bcrl-Abl-Stat5 related malignancies. PMID:27557509

CM363, a novel naphthoquinone derivative which acts as multikinase modulator and overcomes imatinib resistance in chronic myelogenous leukemia.

PubMed

Guerra, Borja; Martín-Rodríguez, Patricia; Díaz-Chico, Juan Carlos; McNaughton-Smith, Grant; Jiménez-Alonso, Sandra; Hueso-Falcón, Idaira; Montero, Juan Carlos; Blanco, Raquel; León, Javier; Rodríguez-González, Germán; Estévez-Braun, Ana; Pandiella, Atanasio; Díaz-Chico, Bonifacio Nicolás; Fernández-Pérez, Leandro

2017-05-02

Human Chronic Myelogenous Leukemia (CML) is a hematological stem cell disorder which is associated with activation of Bcr-Abl-Stat5 oncogenic pathway. Direct Bcr-Abl inhibitors are initially successful for the treatment of CML but over time many patients develop drug resistance. In the present study, the effects of CM363, a novel naphthoquinone (NPQ) derivative, were evaluated on human CML-derived K562 cells. CM363 revealed an effective cell growth inhibition (IC50 = 0.7 ± 0.5 μM) by inducing cancer cells to undergo cell cycle arrest and apoptosis. CM363 caused a dose- and time-dependent reduction of cells in G0/G1 and G2/M phases. This cell cycle arrest was associated with increased levels of cyclin E, pChk1 and pChk2 whereas CM363 downregulated cyclin B, cyclin D3, p27, pRB, Wee1, and BUBR1. CM363 increased the double-strand DNA break marker γH2AX. CM363 caused a time-dependent increase of annexin V-positive cells, DNA fragmentation and increased number of apoptotic nuclei. CM363 triggered the mitochondrial apoptotic pathway as reflected by a release of cytochrome C from mitochondria and induction of the cleavage of caspase-3 and -9, and PARP. CM363 showed multikinase modulatory effects through an early increased JNK phosphorylation followed by inhibition of pY-Bcrl-Abl and pY-Stat5. CM363 worked synergistically with imatinib to inhibit cell viability and maintained its activity in imatinib-resistant cells. Finally, CM363 (10 mg/Kg) suppressed the growth of K562 xenograft tumors in athymic mice. In summary, CM363 is a novel multikinase modulator that offers advantages to circumvent imanitib resistance and might be therapeutically effective in Bcrl-Abl-Stat5 related malignancies.

Diagnostic work up for language testing in patients undergoing awake craniotomy for brain lesions in language areas.

PubMed

Bilotta, Federico; Stazi, Elisabetta; Titi, Luca; Lalli, Diana; Delfini, Roberto; Santoro, Antonio; Rosa, Giovanni

2014-06-01

Awake craniotomy is the technique of choice in patients with brain tumours adjacent to primary and accessory language areas (Broca's and Wernicke's areas). Language testing should be aimed to detect preoperative deficits, to promptly identify the occurrence of new intraoperative impairments and to establish the course of postoperative language status. Aim of this case series is to describe our experience with a dedicated language testing work up to evaluate patients with or at risk for language disturbances undergoing awake craniotomy for brain tumour resection. Pre- and intra operative testing was accomplished with 8 tests. Intraoperative evaluation was accomplished when patients were fully cooperative (Ramsey < 3). Postoperative evaluation was scheduled at early (within 21 days) and long-term follow-up (3-6 months). Twenty consecutive patients were prospectively recruited. Preoperative language testings were normal in 9 patients (45%), showed mild to moderate language deficit in 8 (40%) and severe language deficit or aphasic disorders in 3 (15%). Broca's area was identified in 15 patients, in all cases by counting arrest during stimulation and in 12 cases by naming arrest. In this article we describe our experience using a language testing work up to evaluate - pre, intra and postoperatively - patients undergoing awake craniotomy for brain tumour resection with preoperative language disturbances or at risk for postoperative language deficits. This approach allows a systematic evaluation and recording of language function status and can be accomplished even when a neuropsychologist or speech therapist are not involved in the operation crew.

Arrests for child pornography production: data at two time points from a national sample of U.S. law enforcement agencies.

PubMed

Wolak, Janis; Finkelhor, David; Mitchell, Kimberly J; Jones, Lisa M

2011-08-01

This study collected information on arrests for child pornography (CP) production at two points (2000-2001 and 2006) from a national sample of more than 2,500 law enforcement agencies. In addition to providing descriptive data about an understudied crime, the authors examined whether trends in arrests suggested increasing CP production, shifts in victim populations, and challenges to law enforcement. Arrests for CP production more than doubled from an estimated 402 in 2000-2001 to an estimated 859 in 2006. Findings suggest the increase was related to increased law enforcement activity rather than to growth in the population of CP producers. Adolescent victims increased, but there was no increase in the proportion of arrest cases involving very young victims or violent images. Producers distributed images in 23% of arrest cases, a proportion that did not change over time. This suggests that much CP production may be primarily for private use. Proactive law enforcement operations increased, as did other features consistent with a robust law enforcement response.

Loss of c-myc repression coincides with ovarian cancer resistance to transforming growth factor beta growth arrest independent of transforming growth factor beta/Smad signaling.

PubMed

Baldwin, Rae Lynn; Tran, Hang; Karlan, Beth Y

2003-03-15

Many epithelial carcinomas, including ovarian, are refractory to the antiproliferative effects of transforming growth factor (TGF) beta. In some cancers, TGF-beta resistance has been linked to TGF-beta receptor II (TbetaR-II) and Smad4 mutations; however, in ovarian cancer, the mechanism of resistance remains unclear. Primary ovarian epithelial cell cultures were used as a model system to determine the mechanisms of TGF-beta resistance. To simulate in vivo responses to TGF-beta, primary cultures derived from normal human ovarian surface epithelium (HOSE) and from ovarian carcinomas (CSOC) were grown on collagen I gel, the predominant matrix molecule in the ovarian tumor milieu. When treated with 5 ng/ml TGF-beta for 72 h, HOSE (n = 11) proliferation was inhibited by 20 +/- 21% on average. In contrast, CSOC (n = 10) proliferation was stimulated 5 +/- 10% in response to TGF-beta (a statistically significant difference in response when compared with HOSE; P = 0.001). To dissect the TGF-beta/Smad signaling pathway we used a quantitative RNase protection assay (RPA) for measuring mRNA levels of TGF-beta pathway components in 20 HOSE and 20 CSOC cultures. Basal mRNA levels of TGF-beta receptors I and II, downstream signaling components Smad2, 3, 4, 6, 7, and the transcriptional corepressors Ski and SnoN did not show a statistically significant difference between HOSE and CSOC, and cannot explain their differential susceptibility to TGF-beta-induced cell cycle arrest. To assess functional differences of the TGF-beta pathway in TGF-beta-sensitive HOSE and TGF-beta-resistant CSOC, we measured Smad2/4 and 3/4 complex induction after TGF-beta treatment. HOSE and CSOC showed equivalent Smad2/4 and 3/4 complex induction after TGF-beta exposure for 0, 0.5, 2, and 4 h. It has been proposed that SnoN and Ski are corepressors of the TGF-beta/Smad pathway and undergo TGF-beta-induced degradation followed by reinduction of SnoN mRNA. However, our data show equivalent SnoN degradation in HOSE and CSOC, and equivalent SnoN mRNA induction after TGF-beta treatment. Surprising, TGF-beta-induced Ski degradation was not observed in HOSE or CSOC, suggesting that Ski may not function as a TGF-beta/Smad corepressor in ovarian epithelial cells. These data implied that the TGF-beta/Smad pathway remains functional in CSOC, although CSOC cells are resistant to antimitogenic TGF-beta effects. CSOC resistance to TGF-beta coincided with the loss of c-myc down-regulation. These data suggest that TGF-beta/Smad signaling is blocked downstream of Smad complex formation or that an alternate signaling pathway other than TGF-beta/Smad may transmit TGF-beta-induced cell cycle arrest in the ovarian epithelium.

L-Glycine Alleviates Furfural-Induced Growth Inhibition during Isobutanol Production in Escherichia coli.

PubMed

Song, Hun-Suk; Jeon, Jong-Min; Choi, Yong Keun; Kim, Jun-Young; Kim, Wooseong; Yoon, Jeong-Jun; Park, Kyungmoon; Ahn, Jungoh; Lee, Hongweon; Yang, Yung-Hun

2017-12-28

Lignocellulose is now a promising raw material for biofuel production. However, the lignin complex and crystalline cellulose require pretreatment steps for breakdown of the crystalline structure of cellulose for the generation of fermentable sugars. Moreover, several fermentation inhibitors are generated with sugar compounds, majorly furfural. The mitigation of these inhibitors is required for the further fermentation steps to proceed. Amino acids were investigated on furfural-induced growth inhibition in E. coli producing isobutanol. Glycine and serine were the most effective compounds against furfural. In minimal media, glycine conferred tolerance against furfural. From the IC₅₀ value for inhibitors in the production media, only glycine could alleviate growth arrest for furfural, where 6 mM glycine addition led to a slight increase in growth rate and isobutanol production from 2.6 to 2.8 g/l under furfural stress. Overexpression of glycine pathway genes did not lead to alleviation. However, addition of glycine to engineered strains blocked the growth arrest and increased the isobutanol production about 2.3-fold.

Comparison of neurocognitive results after coronary artery bypass grafting and thoracic aortic surgery using retrograde cerebral perfusion.

PubMed

Miyairi, Takeshi; Takamoto, Shinichi; Kotsuka, Yutaka; Takeuchi, Atsuko; Yamanaka, Katsuo; Sato, Hajime

2005-07-01

Retrograde cerebral perfusion (RCP) is used as an adjunctive method to hypothermic circulatory arrest to enhance cerebral protection in patients undergoing thoracic aortic surgery. It remains unclear whether RCP provides improved neurological and neuropsychological outcome. Forty-six patients undergoing thoracic aortic surgery using RCP, and 28 undergoing coronary artery bypass grafting (CABG; n = 28) with CPB, were enrolled in the study. Patients receiving RCP were subdivided into two groups, those with less than 60 min of RCP (S-RCP; n = 27) and with 60 min or more (L-RCP; n = 19). The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale a few days before operation, at 2-3 weeks and 4-6 months after operation. There were no stroke, seizure, and hospital mortality in either group. Significant decline between baseline and early scores were seen in three subtests (digit span, arithmetic, and picture completion) for S-RCP and four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP. Significant decline between baseline and late scores were seen in one subtest (arithmetic) for S-RCP, four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP, and one (object assembly) for CABG. The mean change of scores for one late test (digit symbol) was significantly lower in S-RCP than in CABG. The mean change of scores for three early tests (digit span, vocabulary, and picture arrangement) and four late tests (information, digit span, picture completion, and picture arrangement) were significantly lower in L-RCP than in CABG. Stepwise logistic regression analysis disclosed that, after considering the other variables, significant difference in test score changes were observed between CABG and L-RCP for two early tests (picture completion and digit symbol) as well as for three late tests (digit span, similarities, and picture completion). None of test score changes showed significant difference between CABG and S-RCP. The neurocognitive outcome in patients undergoing RCP less than 60 min were comparable with patients undergoing CABG without circulatory arrest. Prolonged RCP of 60 min or more in patients undergoing surgery of the thoracic aorta was associated with postoperative neurocognitive impairment.

Jaceosidin, isolated from dietary mugwort (Artemisia princeps), induces G2/M cell cycle arrest by inactivating cdc25C-cdc2 via ATM-Chk1/2 activation.

PubMed

Lee, Jong-Gyu; Kim, Ji-Hyun; Ahn, Ji-Hye; Lee, Kyung-Tae; Baek, Nam-In; Choi, Jung-Hye

2013-05-01

Jaceosidin, a flavonoid derived from Artemisia princeps (Japanese mugwort), has been shown to inhibit the growth of several human cancer cells, However, the exact mechanism for the cytotoxic effect of jaceosidin is not completely understood. In this study, we investigated the molecular mechanism involved in the antiproliferative effect of jaceosidin in human endometrial cancer cells. We demonstrated that jaceosidin is a more potent inhibitor of cell growth than cisplatin in human endometrial cancer cells. In contrast, jaceosidin-induced cytotoxicity in normal endometrial cells was lower than that observed for cisplatin. Jaceosidin induced G2/M phase cell cycle arrest and modulated the levels of cyclin B and p-Cdc2 in Hec1A cells. Knockdown of p21 using specific siRNAs partially abrogated jaceosidin-induced cell growth inhibition. Additional mechanistic studies revealed that jaceosidin treatment resulted in an increase in phosphorylation of Cdc25C and ATM-Chk1/2. Ku55933, an ATM inhibitor, reversed jaceosidin-induced cell growth inhibition, in part. Moreover, jaceosidin treatment resulted in phosphorylation of ERK, and pretreatment with the ERK inhibitor, PD98059, attenuated cell growth inhibition by jaceosidin. These data suggest that jaceosidin, isolated from Japanese mugwort, modulates the ERK/ATM/Chk1/2 pathway, leading to inactivation of the Cdc2-cyclin B1 complex, followed by G2/M cell cycle arrest in endometrial cancer cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

In Vivo Activation of cAMP Signaling Induces Growth Arrest and Differentiation in Acute Promyelocytic Leukemia

PubMed Central

Guillemin, Marie-Claude; Raffoux, Emmanuel; Vitoux, Dominique; Kogan, Scott; Soilihi, Hassane; Lallemand-Breitenbach, Valérie; Zhu, Jun; Janin, Anne; Daniel, Marie-Thérèse; Gourmel, Bernard; Degos, Laurent; Dombret, Hervé; Lanotte, Michel; de Thé, Hugues

2002-01-01

Differentiation therapy for acute myeloid leukemia uses transcriptional modulators to reprogram cancer cells. The most relevant clinical example is acute promyelocytic leukemia (APL), which responds dramatically to either retinoic acid (RA) or arsenic trioxide (As2O3). In many myeloid leukemia cell lines, cyclic adenosine monophosphate (cAMP) triggers growth arrest, cell death, or differentiation, often in synergy with RA. Nevertheless, the toxicity of cAMP derivatives and lack of suitable models has hampered trials designed to assess the in vivo relevance of theses observations. We show that, in an APL cell line, cAMP analogs blocked cell growth and unraveled As2O3-triggered differentiation. Similarly, in RA-sensitive or RA-resistant mouse models of APL, continuous infusions of 8-chloro-cyclic adenosine monophosphate (8-Cl-cAMP) triggered major growth arrest, greatly enhanced both spontaneous and RA- or As2O3-induced differentiation and accelerated the restoration of normal hematopoiesis. Theophylline, a well-tolerated phosphodiesterase inhibitor which stabilizes endogenous cAMP, also impaired APL growth and enhanced spontaneous or As2O3-triggered cell differentiation in vivo. Accordingly, in an APL patient resistant to combined RA–As2O3 therapy, theophylline induced blast clearance and restored normal hematopoiesis. Taken together, these results demonstrate that in vivo activation of cAMP signaling contributes to APL clearance, independently of its RA-sensitivity, thus raising hopes that other myeloid leukemias may benefit from this therapeutic approach. PMID:12438428

Development of the emergency preservation and resuscitation for cardiac arrest from trauma clinical trial.

PubMed

Tisherman, Samuel A; Alam, Hasan B; Rhee, Peter M; Scalea, Thomas M; Drabek, Tomas; Forsythe, Raquel M; Kochanek, Patrick M

2017-11-01

Patients who suffer a cardiac arrest from trauma rarely survive, even with aggressive resuscitation attempts, including an emergency department thoracotomy. Emergency Preservation and Resuscitation (EPR) was developed to utilize hypothermia to buy time to obtain hemostasis before irreversible organ damage occurs. Large animal studies have demonstrated that cooling to tympanic membrane temperature 10°C during exsanguination cardiac arrest can allow up to 2 hours of circulatory arrest and repair of simulated injuries with normal neurologic recovery. The Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma trial has been developed to test the feasibility and safety of initiating EPR. Select surgeons will be trained in the EPR technique. If a trained surgeon is available, the subject will undergo EPR. If not, the subject will be followed as a control subject. For this feasibility study, 10 EPR and 10 control subjects will be enrolled. Study participants will be those with penetrating trauma who remain pulseless despite an emergency department thoracotomy. Emergency Preservation and Resuscitation will be initiated via an intra-aortic flush of a large volume of ice-cold saline solution. Following surgical hemostasis, delayed resuscitation will be accomplished with cardiopulmonary bypass. The primary outcome will be survival to hospital discharge without significant neurologic deficits. Secondary outcomes include long-term survival and functional outcome. Once data from these 20 subjects are reviewed, revisions to the inclusion criteria and/or the EPR technique may then be tested in a second set of EPR and control subjects.

Recovery from DNA damage-induced G2 arrest requires actin-binding protein filamin-A/actin-binding protein 280.

PubMed

Meng, Xiangbing; Yuan, Yuan; Maestas, Adrian; Shen, Zhiyuan

2004-02-13

Filamin-A (filamin-1) is an actin-binding protein involved in the organization of actin networks. Our previous study shows that filamin-A interacts with BRCA2, and lack of filamin-A expression results in increased cellular sensitivity to several DNA damaging agents in melanoma cells (Yuan, Y., and Shen, Z. (2001) J. Biol. Chem. 276, 48318-48324), suggesting a role of filamin-A in DNA damage response. In this report, we demonstrated that deficiency of filamin-A results in an 8-h delay in the recovery from G2 arrest in response to ionizing radiation. However, filamin-A deficiency does not affect the initial activation of the G2/M checkpoint. We also found that filamin-A deficiency results in sustained activation of Chk1 and Chk2 after irradiation. This in turn causes a delay in the dephosphorylation of phospho-Cdc2, which is inhibitory to the G2/M transition. In addition, filamin-A-deficient M2 cells undergo mitotic catastrophe-related nuclear fragmentation after they are released from the G2 arrest. Together, these data suggest a functional role of filamin-A in the recovery from G2 arrest and subsequent mitotic cell death after DNA damage.

Management of simulated maternal cardiac arrest by residents: didactic teaching versus electronic learning.

PubMed

Hards, Andrea; Davies, Sharon; Salman, Aliya; Erik-Soussi, Magda; Balki, Mrinalini

2012-09-01

Successful resuscitation of a pregnant woman undergoing cardiac arrest and survival of the fetus require prompt, high-quality cardiopulmonary resuscitation. The objective of this observational study was to assess management of maternal cardiac arrest by anesthesia residents using high-fidelity simulation and compare subsequent performance following either didactic teaching or electronic learning (e-learning). Twenty anesthesia residents were randomized to receive either didactic teaching (Didactic group, n = 10) or e-learning (Electronic group, n = 10) on maternal cardiac arrest. Baseline management skills were tested using high-fidelity simulation, with repeat simulation testing one month after their teaching intervention. The time from cardiac arrest to start of perimortem Cesarean delivery (PMCD) was measured, and the technical and nontechnical skills scores between the two teaching groups were compared. The median [interquartile range] time to PMCD decreased after teaching, from 4.5 min [3.4 to 5.1 min] to 3.5 min [2.5 to 4.0 min] (P = 0.03), although the change within each group was not statistically significant (Didactic group 4.9 to 3.8 min, P = 0.2; Electronic group 3.9 to 2.5 min, P = 0.07; Didactic group vs Electronic group, P = 1.0). Even after teaching, only 65% of participants started PMCD within four minutes. Technical and nontechnical skills scores improved after teaching in both groups, and there were no differences between the groups. There are gaps in the knowledge and implementation of resuscitation protocols and the recommended modifications for pregnancy among residents. Teaching can improve performance during management of maternal cardiac arrest. Electronic learning and didactic teaching offer similar benefits.

p53 Mediates Vast Gene Expression Changes That Contribute to Poor Chemotherapeutic Response in a Mouse Model of Breast Cancer.

PubMed

Tonnessen-Murray, Crystal; Ungerleider, Nathan A; Rao, Sonia G; Wasylishen, Amanda R; Frey, Wesley D; Jackson, James G

2018-05-28

p53 is a transcription factor that regulates expression of genes involved in cell cycle arrest, senescence, and apoptosis. TP53 harbors mutations that inactivate its transcriptional activity in roughly 30% of breast cancers, and these tumors are much more likely to undergo a pathological complete response to chemotherapy. Thus, the gene expression program activated by wild-type p53 contributes to a poor response. We used an in vivo genetic model system to comprehensively define the p53- and p21-dependent genes and pathways modulated in tumors following doxorubicin treatment. We identified genes differentially expressed in spontaneous mammary tumors harvested from treated MMTV-Wnt1 mice that respond poorly (Trp53+/+) or favorably (Trp53-null) and those that lack the critical senescence/arrest p53 target gene Cdkn1a. Trp53 wild-type tumors differentially expressed nearly 10-fold more genes than Trp53-null tumors after treatment. Pathway analyses showed that genes involved in cell cycle, senescence, and inflammation were enriched in treated Trp53 wild-type tumors; however, no genes/pathways were identified that adequately explain the superior cell death/tumor regression observed in Trp53-null tumors. Cdkn1a-null tumors that retained arrest capacity (responded poorly) and those that proliferated (responded well) after treatment had remarkably different gene regulation. For instance, Cdkn1a-null tumors that arrested upregulated Cdkn2a (p16), suggesting an alternative, p21-independent route to arrest. Live animal imaging of longitudinal gene expression of a senescence/inflammation gene reporter in Trp53+/+ tumors showed induction during and after chemotherapy treatment, while tumors were arrested, but expression rapidly diminished immediately upon relapse. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

A small molecule based on the pRb2/p130 spacer domain leads to inhibition of cdk2 activity, cell cycle arrest and tumor growth reduction in vivo.

PubMed

Bagella, L; Sun, A; Tonini, T; Abbadessa, G; Cottone, G; Paggi, M G; De Luca, A; Claudio, P P; Giordano, A

2007-03-22

One strategy in the development of anticancer therapeutics has been to arrest malignant proliferation through inhibition of the enzymatic activity of cyclin-dependent kinases (cdks), which are key regulatory molecules of the cell cycle. Over the past few years, numerous compounds with remarkable cdk inhibitory activity have been studied in cancer therapy, although it is very difficult to point out the best cdk to target. An excellent candidate appears to be cdk2, whose alteration is a pathogenic hallmark of tumorigenesis. The small molecule described in our study showed an inhibitory effect on the kinase activity of cdk2, a significant growth arrest observed in a colony formation assay and a reduction in the size of the tumor in nude mice, thus suggesting its potential role as a promising new type of mechanism-based antitumor drug, also for the treatment of hyperproliferative disorders.

Malignancy without immortality? Cellular immortalization as a possible late event in melanoma progression

PubMed Central

Soo, Julia K; MacKenzie Ross, Alastair D; Kallenberg, David M; Milagre, Carla; Heung Chong, W; Chow, Jade; Hill, Lucy; Hoare, Stacey; Collinson, Rebecca S; Hossain, Mehnaz; Keith, W Nicol; Marais, Richard; Bennett, Dorothy C

2011-01-01

Cell senescence is a permanent growth arrest following extended proliferation. Cultured cancer cells including metastatic melanoma cells often appear immortal (proliferate indefinitely), while uncultured benign nevi (moles) show senescence markers. Here, with new explantation methods, we investigated which classes of primary pigmented lesions are typically immortal. Nevi yielded a few proliferating cells, consistent with most nevus cells being senescent. No nevus culture (0/28) appeared immortal. Some thin and thick melanoma cultures proved immortal under these conditions, but surprisingly few (4/37). All arrested cultures displayed three senescence markers in some cells: β-galactosidase, nuclear p16, and heterochromatic foci/aggregates. However, melanoma cultures also showed features of telomeric crisis (arrest because of ultrashort telomeres). Moreover, crisis markers including anaphase bridges were frequent in uncultured vertical growth-phase (VGP) melanomas. Conversely, all immortal melanoma cultures expressed telomerase reverse transcriptase and telomerase, showing aneuploidy. The findings suggest that primary melanomas are typically precrisis, with immortalization/telomere maintenance as a late event. PMID:21418545

Skeletal advance and arrest in giant non-metamorphosing African clawed frog tadpoles (Xenopus laevis: Daudin)

PubMed Central

Kerney, Ryan; Wassersug, Richard; Hall, Brian K

2010-01-01

This study examines the skeletons of giant non-metamorphosing (GNM) Xenopus laevis tadpoles, which arrest their development indefinitely before metamorphosis, and grow to excessively large sizes in the absence of detectable thyroid glands. Cartilage growth is isometric; however, chondrocyte size is smaller in GNM tadpoles than in controls. Most cartilages stain weakly with alcian blue, and several cartilages are calcified (unlike controls). However, cartilages subjacent to periosteum-derived bone retain strong affinities for alcian blue, indicating a role for periosteum-derived bone in the retention of glycosaminoglycans during protracted larval growth. Bone formation in the head, limb, and axial skeletons is advanced in comparison with stage-matched controls, but arrests at various mid-metamorphic states. Both dermal and periosteum-derived bones grow to disproportionately large sizes in comparison to controls. Additionally, mature monocuspid teeth form in several GNM tadpoles. Advances in skeletal development are attributable to the old ages and large sizes of these tadpoles, and reveal unexpected developmental potentials of the pre-metamorphic skeleton. PMID:20402828

Synergistic effect of curcumin on epigallocatechin gallate-induced anticancer action in PC3 prostate cancer cells.

PubMed

Eom, Dae-Woon; Lee, Ji Hwan; Kim, Young-Joo; Hwang, Gwi Seo; Kim, Su-Nam; Kwak, Jin Ho; Cheon, Gab Jin; Kim, Ki Hyun; Jang, Hyuk-Jai; Ham, Jungyeob; Kang, Ki Sung; Yamabe, Noriko

2015-08-01

Epigallocatechin gallate (EGCG) and curcumin are well known to naturally-occurring anticancer agents. The aim of this study was to verify the combined beneficial anticancer effects of curcumin and EGCG on PC3 prostate cancer cells, which are resistant to chemotherapy drugs and apoptosis inducers. EGCG showed weaker inhibitory effect on PC3 cell proliferation than two other prostate cancer cell lines, LNCaP and DU145. Co-treatment of curcumin improved antiproliferative effect of EGCG on PC3 cells. The protein expressions of p21 were significantly increased by the co-treatment of EGCG and curcumin, whereas it was not changed by the treatment with each individual compound. Moreover, treatments of EGCG and curcumin arrested both S and G2/M phases of PC3 cells. These results suggest that the enhanced inhibitory effect of EGCG on PC3 cell proliferation by curcumin was mediated by the synergic up-regulation of p21-induced growth arrest and followed cell growth arrest.

The Chinese Herb Isolate Yuanhuacine (YHL-14) Induces G2/M Arrest in Human Cancer Cells by Up-regulating p21 Protein Expression through an p53 Protein-independent Cascade*

PubMed Central

Zhang, Ruowen; Wang, Yulei; Li, Jingxia; Jin, Honglei; Song, Shaojiang; Huang, Chuanshu

2014-01-01

Yuanhuacine (YHL-14), the major component of daphnane diterpene ester isolated from the flower buds of Daphne genkwa, has been reported to have activity against cell proliferation in various cancer cell lines. Nevertheless, the potential mechanism has not been explored yet. Here we demonstrate that YHL-14 inhibits bladder and colon cancer cell growth through up-regulation of p21 expression in an Sp1-dependent manner. We found that YHL-14 treatment resulted in up-regulation of p21 expression and a significant G2/M phase arrest in T24T and HCT116 cells without affecting p53 protein expression and activation. Further studies indicate that p21 induction by YHL-14 occurs at the transcriptional level via up-regulation of Sp1 protein expression. Moreover, our results show that p38 is essential for YHL-14-mediated Sp1 protein stabilization, G2/M growth arrest induction, and anchorage-independent growth inhibition of cancer cells. Taken together, our studies demonstrate a novel mechanism of YHL-14 against cancer cell growth in bladder and colon cancer cell lines, which provides valuable information for the design and synthesis of other new conformation-constrained derivatives on the basis of the structure of YHL-14 for cancer therapy. PMID:24451377

Cyclin D1 Downregulation Contributes to Anti-Cancer Effect of Isorhapontigenin (ISO) on Human Bladder Cancer Cells

PubMed Central

Fang, Yong; Cao, Zipeng; Hou, Qi; Ma, Chen; Yao, Chunsuo; Li, Jingxia; Wu, Xue-Ru; Huang, Chuanshu

2013-01-01

Isorhapontigenin (ISO) is a new derivative of stilbene compound that was isolated from the Chinese herb Gnetum Cleistostachyum, and has been used for treatment of bladder cancers for centuries. In our current studies, we have explored the potential inhibitory effect and molecular mechanisms underlying ISO anti-cancer effects on anchorage-independent growth of human bladder cancer cell lines. We found that ISO showed a significant inhibitory effect on human bladder cancer cell growth and was accompanied with related cell cycle G0/G1 arrest as well as downregulation of Cyclin D1 expression at the transcriptional level in UMUC3 and RT112 cells. Further studies identified that ISO down-regulated Cyclin D1 gene transcription via inhibition of SP1 transactivation. Moreover, ectopic expression of GFP-Cyclin D1 rendered UMUC3 cells resistant to induction of cell cycle G0/G1 arrest and inhibition of cancer cell anchorage-independent growth by ISO treatment. Together, our studies demonstrate that ISO is an active compound that mediates for Gnetum Cleistostachyum’s induction of cell cycle G0/G1 arrest and inhibition of cancer cell anchorage-independent growth through down-regulating SP1/Cyclin D1 axis in bladder cancer cells. Our studies provide a novel insight into understanding the anti-cancer activity of the Chinese herb Gnetum Cleistostachyum and its isolate ISO. PMID:23723126

Brief Report: External Beam Radiation Therapy for the Treatment of Human Pluripotent Stem Cell-Derived Teratomas.

PubMed

Lee, Andrew S; Tang, Chad; Hong, Wan Xing; Park, Sujin; Bazalova-Carter, Magdalena; Nelson, Geoff; Sanchez-Freire, Veronica; Bakerman, Isaac; Zhang, Wendy; Neofytou, Evgenios; Connolly, Andrew J; Chan, Charles K; Graves, Edward E; Weissman, Irving L; Nguyen, Patricia K; Wu, Joseph C

2017-08-01

Human pluripotent stem cells, including human embryonic stem cells (hESCs) and human induced PSCs (hiPSCs), have great potential as an unlimited donor source for cell-based therapeutics. The risk of teratoma formation from residual undifferentiated cells, however, remains a critical barrier to the clinical application of these cells. Herein, we describe external beam radiation therapy (EBRT) as an attractive option for the treatment of this iatrogenic growth. We present evidence that EBRT is effective in arresting growth of hESC-derived teratomas in vivo at day 28 post-implantation by using a microCT irradiator capable of targeted treatment in small animals. Within several days of irradiation, teratomas derived from injection of undifferentiated hESCs and hiPSCs demonstrated complete growth arrest lasting several months. In addition, EBRT reduced reseeding potential of teratoma cells during serial transplantation experiments, requiring irradiated teratomas to be seeded at 1 × 10 3 higher doses to form new teratomas. We demonstrate that irradiation induces teratoma cell apoptosis, senescence, and growth arrest, similar to established radiobiology mechanisms. Taken together, these results provide proof of concept for the use of EBRT in the treatment of existing teratomas and highlight a strategy to increase the safety of stem cell-based therapies. Stem Cells 2017;35:1994-2000. © 2017 AlphaMed Press.

Crack propagation and arrest in CFRP materials with strain softening regions

NASA Astrophysics Data System (ADS)

Dilligan, Matthew Anthony

Understanding the growth and arrest of cracks in composite materials is critical for their effective utilization in fatigue-sensitive and damage susceptible applications such as primary aircraft structures. Local tailoring of the laminate stack to provide crack arrest capacity intermediate to major structural components has been investigated and demonstrated since some of the earliest efforts in composite aerostructural design, but to date no rigorous model of the crack arrest mechanism has been developed to allow effective sizing of these features. To address this shortcoming, the previous work in the field is reviewed, with particular attention to the analysis methodologies proposed for similar arrest features. The damage and arrest processes active in such features are investigated, and various models of these processes are discussed and evaluated. Governing equations are derived based on a proposed mechanistic model of the crack arrest process. The derived governing equations are implemented in a numerical model, and a series of simulations are performed to ascertain the general characteristics of the proposed model and allow qualitative comparison to existing experimental results. The sensitivity of the model and the arrest process to various parameters is investigated, and preliminary conclusions regarding the optimal feature configuration are developed. To address deficiencies in the available material and experimental data, a series of coupon tests are developed and conducted covering a range of arrest zone configurations. Test results are discussed and analyzed, with a particular focus on identification of the proposed failure and arrest mechanisms. Utilizing the experimentally derived material properties, the tests are reproduced with both the developed numerical tool as well as a FEA-based implementation of the arrest model. Correlation between the simulated and experimental results is analyzed, and future avenues of investigation are identified. Utilizing the developed model, a sensitivity study is conducted to assess the current proposed arrest configuration. Optimum distribution and sizing of the arrest zones is investigated, and general design guidelines are developed.

The Constrained Vapor Bubble Experiment - Interfacial Flow Region

NASA Technical Reports Server (NTRS)

Kundan, Akshay; Wayner, Peter C., Jr.; Plawsky, Joel L.

2015-01-01

Internal heat transfer coefficient of the CVB correlated to the presence of the interfacial flow region. Competition between capillary and Marangoni flow caused Flooding and not a Dry-out region. Interfacial flow region growth is arrested at higher power inputs. 1D heat model confirms the presence of interfacial flow region. 1D heat model confirms the arresting phenomena of interfacial flow region Visual observations are essential to understanding.

Beta-catenin-mediated transactivation and cell-cell adhesion pathways are important in curcumin (diferuylmethane)-induced growth arrest and apoptosis in colon cancer cells.

PubMed

Jaiswal, Aruna S; Marlow, Benjamin P; Gupta, Nirupama; Narayan, Satya

2002-12-05

The development of nontoxic natural agents with chemopreventive activity against colon cancer is the focus of investigation in many laboratories. Curcumin (feruylmethane), a natural plant product, possesses such chemopreventive activity, but the mechanisms by which it prevents cancer growth are not well understood. In the present study, we examined the mechanisms by which curcumin treatment affects the growth of colon cancer cells in vitro. Results showed that curcumin treatment causes p53- and p21-independent G(2)/M phase arrest and apoptosis in HCT-116(p53(+/+)), HCT-116(p53(-/-)) and HCT-116(p21(-/-)) cell lines. We further investigated the association of the beta-catenin-mediated c-Myc expression and the cell-cell adhesion pathways in curcumin-induced G(2)/M arrest and apoptosis in HCT-116 cells. Results described a caspase-3-mediated cleavage of beta-catenin, decreased transactivation of beta-catenin/Tcf-Lef, decreased promoter DNA binding activity of the beta-catenin/Tcf-Lef complex, and decreased levels of c-Myc protein. These activities were linked with decreased Cdc2/cyclin B1 kinase activity, a function of the G(2)/M phase arrest. The decreased transactivation of beta-catenin in curcumin-treated HCT-116 cells was unpreventable by caspase-3 inhibitor Z-DEVD-fmk, even though the curcumin-induced cleavage of beta-catenin was blocked in Z-DEVD-fmk pretreated cells. The curcumin treatment also induced caspase-3-mediated degradation of cell-cell adhesion proteins beta-catenin, E-cadherin and APC, which were linked with apoptosis, and this degradation was prevented with the caspase-3 inhibitor. Our results suggest that curcumin treatment impairs both Wnt signaling and cell-cell adhesion pathways, resulting in G(2)/M phase arrest and apoptosis in HCT-116 cells.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chetty, Chandramu; Dontula, Ranadheer; Ganji, Purnachandra Nagaraju

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 reductionmore » 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 effects of SPARC on medulloblastoma tumor cell proliferation.« less

Tributyltin induces cell cycle arrest at G1 phase in the yeast Saccharomyces cerevisiae.

PubMed

Sekito, Takayuki; Sugimoto, Naoko; Ishimoto, Masaya; Kawano-Kawada, Miyuki; Akiyama, Koichi; Nishimoto, Sogo; Sugahara, Takuya; Kakinuma, Yoshimi

2014-04-01

Tributyltin (TBT) has long been recognized as a major environmental pollutant that can cause significant damage to the cellular functions as well as disruption of endocrine homeostasis. TBT induces apoptosis accompanied by production of reactive oxygen species (ROS) in mammalian and yeast cells. We observed that the budding yeast cells exposed to this compound at low concentrations exhibited cell growth arrest, but not cell death. Flow cytometric analysis of yeast cells without synchronization and morphological assessment of cells synchronized at M phase by nocodazole treatment indicated that TBT-exposed Saccharomyces cerevisiae cells were arrested at G1 phase of the cell cycle. This arrest was recovered by the addition of N-acetylcysteine, suggesting the involvement of ROS production by TBT. This is the first study to evaluate the action of TBT on cell cycle events.

4-O-Methylhonokiol Protects HaCaT Cells from TGF-β1-Induced Cell Cycle Arrest by Regulating Canonical and Non-Canonical Pathways of TGF-β Signaling

PubMed Central

Kim, Sang-Cheol; Kang, Jung-Il; Hyun, Jin-Won; Kang, Ji-Hoon; Koh, Young-Sang; Kim, Young-Heui; Kim, Ki-Ho; Ko, Ji-Hee; Yoo, Eun-Sook; Kang, Hee-Kyoung

2017-01-01

4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-β (TGF-β) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-β signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-β-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-β1-induced G1/G0 phase arrest and TGF-β1-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-β1-induced canonical pathway. We observed that ERK phosphorylation by TGF-β1 was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-β1-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-β1-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-β1-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-β1-induced cell cycle arrest. PMID:28190316

Rhododenol and raspberry ketone impair the normal proliferation of melanocytes through reactive oxygen species-dependent activation of GADD45.

PubMed

Kim, Minjeong; Baek, Heung Soo; Lee, Miri; Park, Hyeonji; Shin, Song Seok; Choi, Dal Woong; Lim, Kyung-Min

2016-04-01

Rhododenol or rhododendrol (RD, 4-(4-hydroxyphenyl)-2-butanol) occurs naturally in many plants along with raspberry ketone (RK, 4-(4-hydroxyphenyl)-2-butanone), a ketone derivative, which include Nikko maple tree (Acer nikoense) and white birch (Betula platyphylla). De-pigmenting activity of RD was discovered and it was used as a brightening ingredient for the skin whitening cosmetics. Recently, cosmetics containing RD were withdrawn from the market because a number of consumers developed leukoderma, inflammation and erythema on their face, neck and hands. Here, we explored the mechanism underlying the toxicity of RD and RK against melanocytes using B16F10 murine melanoma cells and human primary epidermal melanocytes. Treatment with RD or RK resulted in the decreased cell viability in a dose-dependent manner which appeared from cell growth arrest. Consistently, ROS generation was significantly increased by RD or RK as determined by DCF-enhanced fluorescence. An antioxidant enzyme, glutathione peroxidase was depleted as well. In line with ROS generation, oxidative damages and the arrest of normal cell proliferation, GADD genes (Growth Arrest and DNA Damage) that include GADD45 and GADD153, were significantly up-regulated. Prevention of ROS generation with an anti-oxidant, N-acetylcysteine (NAC) significantly rescued RD and RK-suppressed melanocyte proliferation. Consistently, up-regulation of GADD45 and GADD153 was significantly attenuated by NAC, suggesting that increased ROS and the resultant growth arrest of melanocytes may contribute to RD and RK-induced leukoderma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hypoxia in cartilage: HIF-1alpha is essential for chondrocyte growth arrest and survival.

PubMed

Schipani, E; Ryan, H E; Didrickson, S; Kobayashi, T; Knight, M; Johnson, R S

2001-11-01

Breakdown or absence of vascular oxygen delivery is a hallmark of many common human diseases, including cancer, myocardial infarction, and stroke. The chief mediator of hypoxic response in mammalian tissues is the transcription factor hypoxia-inducible factor 1 (HIF-1), and its oxygen-sensitive component HIF-1alpha. A key question surrounding HIF-1alpha and the hypoxic response is the role of this transcription factor in cells removed from a functional vascular bed; in this regard there is evidence indicating that it can act as either a survival factor or induce growth arrest and apoptosis. To study more closely how HIF-1alpha functions in hypoxia in vivo, we used tissue-specific targeting to delete HIF-1alpha in an avascular tissue: the cartilaginous growth plate of developing bone. We show here the first evidence that the developmental growth plate in mammals is hypoxic, and that this hypoxia occurs in its interior rather than at its periphery. As a result of this developmental hypoxia, cells that lack HIF-1alpha in the interior of the growth plate die. This is coupled to decreased expression of the CDK inhibitor p57, and increased levels of BrdU incorporation in HIF-1alpha null growth plates, indicating defects in HIF-1alpha-regulated growth arrest occurs in these animals. Furthermore, we find that VEGF expression in the growth plate is regulated through both HIF-1alpha-dependent and -independent mechanisms. In particular, we provide evidence that VEGF expression is up-regulated in a HIF-1alpha-independent manner in chondrocytes surrounding areas of cell death, and this in turn induces ectopic angiogenesis. Altogether, our findings have important implications for the role of hypoxic response and HIF-1alpha in development, and in cell survival in tissues challenged by interruption of vascular flow; they also illustrate the complexities of HIF-1alpha response in vivo, and they provide new insights into mechanisms of growth plate development.

SLC6A4 expression and anti-proliferative responses to serotonin transporter ligands chlomipramine and fluoxetine in primary B-cell malignancies.

PubMed

Chamba, Anita; Holder, Michelle J; Jarrett, Ruth F; Shield, Lesley; Toellner, Kai M; Drayson, Mark T; Barnes, Nicholas M; Gordon, John

2010-08-01

B-cell lines of diverse neoplastic origin express the serotonin transporter (SERT/SLC6A4) and growth arrest in response to SERT-ligands, including the antidepressants chlomipramine and fluoxetine. Here we detail SLC6A4 transcript (Q-PCR) and protein (FACS) expression in primary cells from patients with: chronic lymphocytic leukaemia; mantle cell lymphoma; follicular lymphoma; Burkitt's lymphoma; and diffuse large B-cell lymphoma. The ability of the SERT-binding antidepressants to impact the growth of these cells when sustained on CD154-transfected fibroblasts was also determined. The results reveal a broad spectrum of primary B-cell malignancies expressing SLC6A4 with a proportion additionally displaying growth arrest on SERT-ligand exposure. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Physeal growth arrest after tibial lengthening in achondroplasia

PubMed Central

2012-01-01

Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

PubMed

Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

2012-06-01

Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with achondroplasia. We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence-especially when lengthening of more than 50% is attempted.

Proteasome inhibition enhances the efficacy of volasertib-induced mitotic arrest in AML in vitro and prolongs survival in vivo.

PubMed

Schnerch, Dominik; Schüler, Julia; Follo, Marie; Felthaus, Julia; Wider, Dagmar; Klingner, Kathrin; Greil, Christine; Duyster, Justus; Engelhardt, Monika; Wäsch, Ralph

2017-03-28

Elderly and frail patients, diagnosed with acute myeloid leukemia (AML) and ineligible to undergo intensive treatment, have a dismal prognosis. The small molecule inhibitor volasertib induces a mitotic block via inhibition of polo-like kinase 1 and has shown remarkable anti-leukemic activity when combined with low-dose cytarabine. We have demonstrated that AML cells are highly vulnerable to cell death in mitosis yet manage to escape a mitotic block through mitotic slippage by sustained proteasome-dependent slow degradation of cyclin B. Therefore, we tested whether interfering with mitotic slippage through proteasome inhibition arrests and kills AML cells more efficiently during mitosis. We show that therapeutic doses of bortezomib block the slow degradation of cyclin B during a volasertib-induced mitotic arrest in AML cell lines and patient-derived primary AML cells. In a xenotransplant mouse model of human AML, mice receiving volasertib in combination with bortezomib showed superior disease control compared to mice receiving volasertib alone, highlighting the potential therapeutic impact of this drug combination.

Transcriptional, translational, and physiological signatures of undernourished honey bees (Apis mellifera) suggest a role for hormonal factors in hypopharyngeal gland degradation.

PubMed

Corby-Harris, Vanessa; Meador, Charlotte A D; Snyder, Lucy A; Schwan, Melissa R; Maes, Patrick; Jones, Beryl M; Walton, Alexander; Anderson, Kirk E

2016-02-01

Honey bee colonies function as a superorganism, where facultatively sterile female workers perform various tasks that support the hive. Nurse workers undergo numerous anatomical and physiological changes in preparation for brood rearing, including the growth of hypopharyngeal glands (HGs). These glands produce the major protein fraction of a protein- and lipid-rich jelly used to sustain developing larvae. Pollen intake is positively correlated with HG growth, but growth in the first three days is similar regardless of diet, suggesting that initial growth is a pre-determined process while later HG development depends on nutrient availability during a critical window in early adulthood (>3 d). It is unclear whether the resultant size differences in nurse HG are simply due to growth arrest or active degradation of the tissue. To determine what processes cause such differences in HG size, we catalogued the differential expression of both gene transcripts and proteins in the HGs of 8 d old bees that were fed diets containing pollen or no pollen. 3438 genes and 367 proteins were differentially regulated due to nutrition. Of the genes and proteins differentially expressed, undernourished bees exhibited more gene and protein up-regulation compared to well-nourished bees, with the affected processes including salivary gland apoptosis, oogenesis, and hormone signaling. Protein secretion was virtually the only process up-regulated in well-nourished bees. Further assays demonstrated that inhibition of ultraspiracle, one component of the ecdysteroid receptor, in the fat body caused larger HGs. Undernourished bees also had higher acid phosphatase activity, a physiological marker of cell death, compared to well-nourished bees. These results support a connection between poor nutrition, hormonal signaling, and HG degradation. Published by Elsevier Ltd.

Drug screens based on the newly found role of dystroglycan proteolysis and restoration of dystroglycan function thereof

DOEpatents

Bissell, Mina J.; Muschler, John L.

2010-02-23

The present invention provides methods and compositions for the diagnosis and treatment of cells lacking normal growth arresting characteristic. The present invention demonstrates that many tumor cells lack normal cell surface .alpha.-dystroglycan and thereby lack dystroglycan function. Dystroglycan can be lost from the cell surface by proteolytic shedding of a fragment of .alpha.-dystroglycan into the surrounding medium. Upon restoration of dystroglycan function and over-expression of the dystroglycan gene, the once tumorigenic cells revert to non-tumorigenic cells which polarize and arrest cell growth in the presence of basement membrane proteins, demonstrating that dystroglycan functions as a tumor marker and suppressor.

The activation of G protein-coupled receptor 30 (GPR30) inhibits proliferation of estrogen receptor-negative breast cancer cells in vitro and in vivo.

PubMed

Wei, W; Chen, Z-J; Zhang, K-S; Yang, X-L; Wu, Y-M; Chen, X-H; Huang, H-B; Liu, H-L; Cai, S-H; Du, J; Wang, H-S

2014-10-02

There is an urgent clinical need for safe and effective treatment agents and therapy targets for estrogen receptor negative (ER-) breast cancer. G protein-coupled receptor 30 (GPR30), which mediates non-genomic signaling of estrogen to regulate cell growth, is highly expressed in ER--breast cancer cells. We here showed that activation of GPR30 by the receptor-specific agonist G-1 inhibited the growth of ER--breast cancer cells in vitro. Treatment of ER--breast cancer cells with G-1 resulted in G2/M-phase arrest, downregulation of G2-checkpoint regulator cyclin B, and induction of mitochondrial-related apoptosis. The G-1 treatment increased expression of p53 and its phosphorylation levels at Serine 15, promoted its nuclear translocation, and inhibited its ubiquitylation, which mediated the growth arrest effects on cell proliferation. Further, the G-1 induced sustained activation and nuclear translocation of ERK1/2, which was mediated by GPR30/epidermal growth factor receptor (EGFR) signals, also mediated its inhibition effects of G-1. With extensive use of siRNA-knockdown experiments and inhibitors, we found that upregulation of p21 by the cross-talk of GPR30/EGFR and p53 was also involved in G-1-induced cell growth arrest. In vivo experiments showed that G-1 treatment significantly suppressed the growth of SkBr3 xenograft tumors and increased the survival rate, associated with proliferation suppression and upregulation of p53, p21 while downregulation of cyclin B. The discovery of multiple signal pathways mediated the suppression effects of G-1 makes it a promising candidate drug and lays the foundation for future development of GPR30-based therapies for ER- breast cancer treatment.

Development and growth of fruit bodies and crops of the button mushroom, Agaricus bisporus.

PubMed

Straatsma, Gerben; Sonnenberg, Anton S M; van Griensven, Leo J L D

2013-10-01

We studied the appearance of fruit body primordia, the growth of individual fruit bodies and the development of the consecutive flushes of the crop. Relative growth, measured as cap expansion, was not constant. It started extremely rapidly, and slowed down to an exponential rate with diameter doubling of 1.7 d until fruit bodies showed maturation by veil breaking. Initially many outgrowing primordia were arrested, indicating nutritional competition. After reaching 10 mm diameter, no growth arrest occurred; all growing individuals, whether relatively large or small, showed an exponential increase of both cap diameter and biomass, until veil breaking. Biomass doubled in 0.8 d. Exponential growth indicates the absence of competition. Apparently there exist differential nutritional requirements for early growth and for later, continuing growth. Flushing was studied applying different picking sizes. An ordinary flushing pattern occurred at an immature picking size of 8 mm diameter (picking mushrooms once a day with a diameter above 8 mm). The smallest picking size yielded the highest number of mushrooms picked, confirming the competition and arrested growth of outgrowing primordia: competition seems less if outgrowing primordia are removed early. The flush duration (i.e. between the first and last picking moments) was not affected by picking size. At small picking size, the subsequent flushes were not fully separated in time but overlapped. Within 2 d after picking the first individuals of the first flush, primordia for the second flush started outgrowth. Our work supports the view that the acquisition of nutrients by the mycelium is demand rather than supply driven. For formation and early outgrowth of primordia, indications were found for an alternation of local and global control, at least in the casing layer. All these data combined, we postulate that flushing is the consequence of the depletion of some unknown specific nutrition required by outgrowing primordia. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Prediction of the outcome in cardiac arrest patients undergoing hypothermia using EEG wavelet entropy.

PubMed

Moshirvaziri, Hana; Ramezan-Arab, Nima; Asgari, Shadnaz

2016-08-01

Cardiac arrest (CA) is the leading cause of death in the United States. Induction of hypothermia has been found to improve the functional recovery of CA patients after resuscitation. However, there is no clear guideline for the clinicians yet to determine the prognosis of the CA when patients are treated with hypothermia. The present work aimed at the development of a prognostic marker for the CA patients undergoing hypothermia. A quantitative measure of the complexity of Electroencephalogram (EEG) signals, called wavelet sub-band entropy, was employed to predict the patients' outcomes. We hypothesized that the EEG signals of the patients who survived would demonstrate more complexity and consequently higher values of wavelet sub-band entropies. A dataset of 16-channel EEG signals collected from CA patients undergoing hypothermia at Long Beach Memorial Medical Center was used to test the hypothesis. Following preprocessing of the signals and implementation of the wavelet transform, the wavelet sub-band entropies were calculated for different frequency bands and EEG channels. Then the values of wavelet sub-band entropies were compared among two groups of patients: survived vs. non-survived. Our results revealed that the brain high frequency oscillations (between 64100 Hz) captured from the inferior frontal lobes are significantly more complex in the CA patients who survived (p-value <; 0.02). Given that the non-invasive measurement of EEG is part of the standard clinical assessment for CA patients, the results of this study can enhance the management of the CA patients treated with hypothermia.

Central Anticholinergic Syndrome due to Hypoxia-Induced Bradycardia in a Child with Difficult Intubation Undergoing Complete Dental Restoration: A Case Report.

PubMed

Gharavifard, Mohamad; Razavi, Majid; Ghandehari Motlagh, Mehdi; Ziyaeifard, Mohsen

2014-09-01

Central anticholinergic syndrome (CAS) following general anesthesia (GA) is a well known syndrome in children and adults. Many cases of CAS have been previously reported in the literature. However, there are only two reports of post resuscitation CAS after administration of small doses of atropine. Hereby, we report a case of CAS in a child undergoing complete dental restoration under GA after receiving a small dose of atropine to reverse hypoxia induced bradycardia. Intraoperative events such as hypoxia or cardiac arrest may play a role as triggers for CAS. However, we cannot establish a causal relationship between the occurrence of CAS and such critical events.

The evolution of plasticity of dauer larva developmental arrest in the nematode Caenorhabditis elegans.

PubMed

Diaz, S Anaid; Viney, Mark

2015-03-01

Organisms can end up in unfavourable conditions and to survive this they have evolved various strategies. Some organisms, including nematodes, survive unfavourable conditions by undergoing developmental arrest. The model nematode Caenorhabditis elegans has a developmental choice between two larval forms, and it chooses to develop into the arrested dauer larva form in unfavourable conditions (specifically, a lack of food and high population density, indicated by the concentration of a pheromone). Wild C. elegans isolates vary extensively in their dauer larva arrest phenotypes, and this prompts the question of what selective pressures maintain such phenotypic diversity? To investigate this we grew C. elegans in four different environments, consisting of different combinations of cues that can induce dauer larva development: two combinations of food concentration (high and low) in the presence or absence of a dauer larva-inducing pheromone. Five generations of artificial selection of dauer larvae resulted in an overall increase in dauer larva formation in most selection regimes. The presence of pheromone in the environment selected for twice the number of dauer larvae, compared with environments not containing pheromone. Further, only a high food concentration environment containing pheromone increased the plasticity of dauer larva formation. These evolutionary responses also affected the timing of the worms' reproduction. Overall, these results give an insight into the environments that can select for different plasticities of C. elegans dauer larva arrest phenotypes, suggesting that different combinations of environmental cues can select for the diversity of phenotypically plastic responses seen in C. elegans.

Cell cycle arrest and the evolution of chronic kidney disease from acute kidney injury.

PubMed

Canaud, Guillaume; Bonventre, Joseph V

2015-04-01

For several decades, acute kidney injury (AKI) was generally considered a reversible process leading to complete kidney recovery if the individual survived the acute illness. Recent evidence from epidemiologic studies and animal models, however, have highlighted that AKI can lead to the development of fibrosis and facilitate the progression of chronic renal failure. When kidney injury is mild and baseline function is normal, the repair process can be adaptive with few long-term consequences. When the injury is more severe, repeated, or to a kidney with underlying disease, the repair can be maladaptive and epithelial cell cycle arrest may play an important role in the development of fibrosis. Indeed, during the maladaptive repair after a renal insult, many tubular cells that are undergoing cell division spend a prolonged period in the G2/M phase of the cell cycle. These tubular cells recruit intracellular pathways leading to the synthesis and the secretion of profibrotic factors, which then act in a paracrine fashion on interstitial pericytes/fibroblasts to accelerate proliferation of these cells and production of interstitial matrix. Thus, the tubule cells assume a senescent secretory phenotype. Characteristic features of these cells may represent new biomarkers of fibrosis progression and the G2/M-arrested cells may represent a new therapeutic target to prevent, delay or arrest progression of chronic kidney disease. Here, we summarize recent advances in our understanding of the biology of the cell cycle and how cell cycle arrest links AKI to chronic kidney disease. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

PKCalpha-mediated ERK, JNK and p38 activation regulates the myogenic program in human rhabdomyosarcoma cells.

PubMed

Mauro, Annunziata; Ciccarelli, Carmela; De Cesaris, Paola; Scoglio, Arianna; Bouché, Marina; Molinaro, Mario; Aquino, Angelo; Zani, Bianca Maria

2002-09-15

We have previously suggested that PKCalpha has a role in 12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated growth arrest and myogenic differentiation in human embryonal rhabdomyosarcoma cells (RD). Here, by monitoring the signalling pathways triggered by TPA, we demonstrate that PKCalpha mediates these effects by inducing transient activation of c-Jun N-terminal protein kinases (JNKs) and sustained activation of both p38 kinase and extracellular signal-regulated kinases (ERKs) (all referred to as MAPKs). Activation of MAPKs following ectopic expression of constitutively active PKCalpha, but not its dominant-negative form, is also demonstrated. We investigated the selective contribution of MAPKs to growth arrest and myogenic differentiation by monitoring the activation of MAPK pathways, as well as by dissecting MAPK pathways using MEK1/2 inhibitor (UO126), p38 inhibitor (SB203580) and JNK and p38 agonist (anisomycin) treatments. Growth-arresting signals are triggered either by transient and sustained JNK activation (by TPA and anisomycin, respectively) or by preventing both ERK and JNK activation (UO126) and are maintained, rather than induced, by p38. We therefore suggest a key role for JNK in controlling ERK-mediated mitogenic activity. Notably, sarcomeric myosin expression is induced by both TPA and UO126 but is abrogated by the p38 inhibitor. This finding indicates a pivotal role for p38 in controlling the myogenic program. Anisomycin persistently activates p38 and JNKs but prevents myosin expression induced by TPA. In accordance with this negative role, reactivation of JNKs by anisomycin, in UO126-pre-treated cells, also prevents myosin expression. This indicates that, unlike the transient JNK activation that occurs in the TPA-mediated myogenic process, long-lasting JNK activation supports the growth-arrest state but antagonises p38-mediated myosin expression. Lastly, our results with the MEK inhibitor suggest a key role of the ERK pathway in regulating myogenic-related morphology in differentiated RD cells.

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

PubMed Central

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

2016-01-01

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

c-Myc plays a key role in TADs-induced apoptosis and cell cycle arrest in human hepatocellular carcinoma cells.

PubMed

Zhang, Dongdong; Qi, Junpeng; Liu, Rui; Dai, Bingling; Ma, Weina; Zhan, Yingzhuan; Zhang, Yanmin

2015-01-01

Cancer cell growth is complicated progression which is regulated and controlled by multiple factors including cell cycle, migration and apoptosis. In present study, we report that TADs, a novel derivative of taspine, has an essential role in resisting hepatocellular carcinoma growth (including arrest cell cycle) and migration, and inducing cell apoptosis. Our findings demonstrated that the TADs showed good inhibition on the hepatoma cell growth and migration, and good action on apoptosis induction. Using genome-wide microarray analysis, we found the down-regulated growth and apoptosis factors, and selected down-regulated genes were confirmed by Western blot. Knockdown of a checkpoint c-Myc by siRNA significantly attenuated tumor inhibition and apoptosis effects of TADs. Moreover, our results indicated TADs could simultaneously increase cyclin D1 protein levels and decrease amount of cyclin E, cyclin B1 and cdc2 of the cycle proteins, and also TADs reduced Bcl-2 expression, and upregulated Bad, Bak and Bax activities. In conclusion, these results illustrated that TADs is a key factor in growth and apoptosis signaling inhibitor, has potential in cancer therapy.

A superoxide anion generator, pyrogallol, inhibits the growth of HeLa cells via cell cycle arrest and apoptosis.

PubMed

Kim, Sang Wook; Han, Yong Whan; Lee, Soo Teik; Jeong, Hey Jin; Kim, Seong Hun; Kim, In Hee; Lee, Seung Ok; Kim, Dae Ghon; Kim, Suhn Hee; Kim, Sung Zoo; Park, Woo Hyun

2008-02-01

We investigated the in vitro effects of pyrogallol on cell growth, cell cycle regulation, and apoptosis in HeLa cells. Pyrogallol inhibited the growth of HeLa cells with an IC(50) of approximately 45 microM. Pyrogallol induced arrest during all phases of the cell cycle and also very efficiently resulted in apoptosis in HeLa cells, as evidenced by flow cytometric detection of sub-G1 DNA content, annexin V binding assay, and DAPI staining. This apoptotic process was accompanied by the loss of mitochondrial transmembrane potential (DeltaPsi(m)), Bcl-2 decrease, caspase-3 activation, and PARP cleavage. Pan-caspase inhibitor (Z-VAD) could rescue some HeLa cells from pyrogallol-induced cell death, while caspase-8 and -9 inhibitors unexpectedly enhanced the apoptosis. When we examined the changes of the ROS, H(2)O(2) or O(2)(*-) in pyrogallol-treated cells, H(2)O(2) was slightly increased and O(2)(*-) significantly was increased. In addition, we detected a decreased GSH content in pyrogallol-treated cells. Only pan-caspase inhibitor showing recovery of GSH depletion and reduced intracellular O(2)(*-) level decreased PI staining in pyrogallol-treated HeLa cells, which indicates dead cells. In summary, we have demonstrated that pyrogallol as a generator of ROS, especially O(2) (*-), potently inhibited the growth of HeLa cells through arrests during all phases of the cell cycle and apoptosis. (c) 2007 Wiley-Liss, Inc.

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

PubMed

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

2013-12-01

Tangeretin (TAN) and 5-demethyltangeretin (5DT) are two closely related polymethoxyflavones found in citrus fruits. We investigated growth inhibitory effects on three human nonsmall cell lung cancer (NSCLC) cells. Cell viability assay demonstrated that 5DT inhibited NSCLC cell growth in a time- and dose-dependent manner, and IC50 s of 5DT were 79-fold, 57-fold, and 56-fold lower than those of TAN in A549, H460, and H1299 cells, respectively. Flow cytometry analysis showed that 5DT induced extensive G2/M cell cycle arrest and apoptosis in NSCLC cells, while TAN at tenfold higher concentrations did not. The apoptosis induced by 5DT was further confirmed by activation of caspase-3 and cleavage of PARP. Moreover, 5DT dose-dependently upregulated p53 and p21(Cip1/Waf1), and downregulated Cdc-2 (Cdk-1) and cyclin B1. HPLC analysis revealed that the intracellular levels of 5DT in NSCLC cells were 2.7-4.9 fold higher than those of TAN after the cells were treated with 5DT or TAN at the same concentration. Our results demonstrated that 5DT inhibited NSCLC cell growth by inducing G2/M cell cycle arrest and apoptosis. These effects were much stronger than those produced by TAN, which is partially due to the higher intracellular uptake of 5DT than TAN. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Anisomycin-induced GATA-6 degradation accompanying a decrease of proliferation of colorectal cancer cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ushijima, Hironori; Horyozaki, Akiko; Maeda, Masatomo, E-mail: mmaeda@nupals.ac.jp

Transcription factor GATA-6 plays a key role in normal cell differentiation of the mesoderm and endoderm. On the other hand, GATA-6 is abnormally overexpressed in many clinical gastrointestinal cancer tissue samples, and accelerates cell proliferation or an anti-apoptotic response in cancerous tissues. We previously showed that activation of the JNK signaling cascade causes proteolysis of GATA-6. In this study, we demonstrated that anisomycin, a JNK activator, stimulates nuclear export of GATA-6 in a colorectal cancer cell line, DLD-1. Concomitantly, anisomycin remarkably inhibits the proliferation of DLD-1 cells via G2/M arrest in a plate culture. However, it did not induce apoptosis undermore » growth arrest conditions. Furthermore, the growth of DLD-1 cells in a spheroid culture was suppressed by anisomycin. Although 5-FU showed only a slight inhibitory effect on 3D spheroid cultures, the same concentration of 5-FU together with a low concentration of anisomycin exhibited strong growth inhibition. These results suggest that the induction of GATA-6 dysfunction may be more effective for chemotherapy for colorectal cancer, although the mechanism underlying the synergistic effect of 5-FU and anisomycin remains unknown. - Highlights: • Anisomycin induces proteolysis of GATA-6 in DLD-1 cells. • Anisomycin remarkably inhibits the proliferation of DLD-1 cells via G2/M arrest. • Anisomycin suppresses the growth of spheroids of DLD-1, and enhances the effect of 5-FU.« less

Essential Roles of Raf/Extracellular Signal-regulated Kinase/Mitogen-activated Protein Kinase Pathway, YY1, and Ca2+ Influx in Growth Arrest of Human Vascular Smooth Muscle Cells by Bilirubin*

PubMed Central

Stoeckius, Marlon; Erat, Anna; Fujikawa, Tatsuya; Hiromura, Makoto; Koulova, Anna; Otterbein, Leo; Bianchi, Cesario; Tobiasch, Edda; Dagon, Yossi; Sellke, Frank W.; Usheva, Anny

2012-01-01

The biological effects of bilirubin, still poorly understood, are concentration-dependent ranging from cell protection to toxicity. Here we present data that at high nontoxic physiological concentrations, bilirubin inhibits growth of proliferating human coronary artery smooth muscle cells by three events. It impairs the activation of Raf/ERK/MAPK pathway and the cellular Raf and cyclin D1 content that results in retinoblastoma protein hypophosphorylation on amino acids S608 and S780. These events impede the release of YY1 to the nuclei and its availability to regulate the expression of genes and to support cellular proliferation. Moreover, altered calcium influx and calpain II protease activation leads to proteolytical degradation of transcription factor YY1. We conclude that in the serum-stimulated human vascular smooth muscle primary cell cultures, bilirubin favors growth arrest, and we propose that this activity is regulated by its interaction with the Raf/ERK/MAPK pathway, effect on cyclin D1 and Raf content, altered retinoblastoma protein profile of hypophosphorylation, calcium influx, and YY1 proteolysis. We propose that these activities together culminate in diminished 5 S and 45 S ribosomal RNA synthesis and cell growth arrest. The observations provide important mechanistic insight into the molecular mechanisms underlying the transition of human vascular smooth muscle cells from proliferative to contractile phenotype and the role of bilirubin in this transition. PMID:22262839

Using growth and arrest of Richtmyer-Meshkov instabilities and Lagrangian simulations to study high-rate material strength

NASA Astrophysics Data System (ADS)

Prime, M. B.; Vaughan, D. E.; Preston, D. L.; Buttler, W. T.; Chen, S. R.; Oró, D. M.; Pack, C.

2014-05-01

Experiments applying a supported shock through mating surfaces (Atwood number = 1) with geometrical perturbations have been proposed for studying strength at strain rates up to 107/s using Richtmyer-Meshkov (RM) instabilities. Buttler et al. recently reported experimental results for RM instability growth in copper but with an unsupported shock applied by high explosives and the geometrical perturbations on the opposite free surface (Atwood number = -1). This novel configuration allowed detailed experimental observation of the instability growth and arrest. We present results and interpretation from numerical simulations of the Buttler RM instability experiments. Highly-resolved, two-dimensional simulations were performed using a Lagrangian hydrocode and the Preston-Tonks-Wallace (PTW) strength model. The model predictions show good agreement with the data. The numerical simulations are used to examine various assumptions previously made in an analytical model and to estimate the sensitivity of such experiments to material strength.

GAS6 Receptor Status Is Associated with Dormancy and Bone Metastatic Tumor Formation

PubMed Central

Taichman, Russell S.; Patel, Lalit R.; Bedenis, Rachel; Wang, Jingcheng; Weidner, Savannah; Schumann, Taibriana; Yumoto, Kenji; Berry, Janice E.; Shiozawa, Yusuke; Pienta, Kenneth J.

2013-01-01

Disseminated tumor cells (DTCs) are believed to lie dormant in the marrow before they can be activated to form metastases. How DTCs become dormant in the marrow and how dormant DTCs escape dormancy remains unclear. Recent work has shown that prostate cancer (PCa) cell lines express the growth-arrest specific 6 (GAS6) receptors Axl, Tyro3, and Mer, and become growth arrested in response to GAS6. We therefore hypothesized that GAS6 signaling regulates the proliferative activity of DTCs in the marrow. To explore this possibility, in vivo studies were performed where it was observed that when Tyro3 expression levels exceed Axl expression, the PCa cells exhibit rapid growth. When when Axl levels predominate, PCa cells remain largely quiescent. These findings suggest that a balance between the expression of Axl and Tyro3 is associated with a molecular switch between a dormant and a proliferative phenotype in PCa metastases. PMID:23637920

The 'trampoline ankle': severe medial malleolar physeal injuries in children and adolescents secondary to multioccupant use of trampolines.

PubMed

Blumetti, Francesco C; Gauthier, Luke; Moroz, Paul J

2016-03-01

The purpose of this study was to describe a series of patients presenting with medial malleolus Salter-Harris types III and IV fractures (MacFarland fractures) related to trampoline use. In total, 11 patients were reviewed retrospectively (mean age: 11.8 years; four boys and seven girls). Salter-Harris type III fractures were more commonly seen (n=7). Undisplaced fractures were more prevalent (n=6). Six children underwent surgical treatment. Average follow-up time was 17.8 months. A medial physeal bar with subsequent growth arrest and ankle deformity was observed in two patients. More than one user was present on the trampoline at the time of the injury in nine of the reported cases. Medial malleolus growth-plate injuries can be seen after trampoline injuries where multiple users were involved. Potential complications including growth arrest can occur.

Rolling and aging in temperature-ramp soft adhesion

NASA Astrophysics Data System (ADS)

Boniello, Giuseppe; Tribet, Christophe; Marie, Emmanuelle; Croquette, Vincent; Zanchi, Dražen

2018-01-01

Immediately before adsorption to a horizontal substrate, sinking polymer-coated colloids can undergo a complex sequence of landing, jumping, crawling, and rolling events. Using video tracking, we studied the soft adhesion to a horizontal flat plate of micron-size colloids coated by a controlled molar fraction f of the poly(lysine)-grafted-poly(N-isopropylacrylamide) (PLL-g-PNIPAM) which is a temperature-sensitive polymer. We ramp the temperature from below to above Tc=32 ±1∘C , at which the PNIPAM polymer undergoes a transition, triggering attractive interaction between microparticles and surface. The adsorption rate, the effective in-plane (x -y ) diffusion constant, and the average residence time distribution over z were extracted from the Brownian motion records during last seconds before immobilization. Experimental data are understood within a rate-equations-based model that includes aging effects and includes three populations: the untethered, the rolling, and the arrested colloids. We show that preadsorption dynamics casts a characteristic scaling function α (f ) proportional to the number of available PNIPAM patches met by soft contact during Brownian rolling. In particular, the increase of in-plane diffusivity with increasing f is understood: The stickiest particles have the shortest rolling regime prior to arrest, so that their motion is dominated by the untethered phase.

Tamoxifen-loaded liposomal topical formulation arrests hair growth in mice.

PubMed

Bhatia, A; Singh, B; Amarji, B; Katare, O P

2010-08-01

For several decades, androgens have dominated endocrine research in the domain of hair growth control. However, it has long been known that oestrogens also tend to alter hair follicle (HF) growth and cycling significantly by binding to locally expressed high-affinity oestrogen receptors (ORs). Tamoxifen (TAM) is a selective OR modulator. The current work aims to investigate the effect of topically applied TAM on the hair growth of mice. Test formulations were applied once daily on the shaved back area of the mice for a period of 5 weeks. The effect of these formulations was studied by visual and histological examinations. Animals treated with saline and placebo gel formulation showed significant hair growth on the 20th day. The number and length of follicles were also found to be normal. In contrast, no hair growth was observed in the animals treated with TAM gel, even after the termination of treatment. The HFs were found to be arrested in telogen phase with clear signs of follicle dystrophy. The hair growth-retarding effect of TAM observed in the current study clearly demonstrates its OR agonistic effect on hair growth. This work also provides a distinct lead towards the possible potential of TAM liposomal gel in the treatment of hirsutism.

The effects of ethanol and strontium on growth and development of two-cell arrested mouse embryos.

PubMed

Darabi, Mohammad Reza; Shiravi, Abdolhossein; Hojati, Vida

2012-01-01

Arresting at a certain stage of development like the two-cell stage could be one of the causes of infertility. The aim of this study is to evaluate the effects of ethanol and strontium on growth and development of mice embryos arrested at the two-cell stage. In this experimental study, female mice were coupled with a male following superovulation. Positive vaginal plug mice were sacrificed 48 hours after human chorionic gonadotropin (hCG) injection. Two-cell embryos were transferred to M16 medium and divided to four groups. The first control group was incubated without any exposure to low temperatures. Groups 2, 3 and 4 were exposed to 4°C for 24 hours. The second control group was incubated immediately, while the third and fourth groups were exposed to 10 mM strontium for five minutes and 0.1% ethanol for a further five minutes. Growth rate and developmental parameters of embryos were analyzed by one- way ANOVA. The significant difference between the groups was determined by Post Hoc. The data shows that developmental rate is decreased significantly by 4°C exposure. The mean percentage of degenerated embryo was significantly different between groups but the mean cleavage rate was not significantly different. The mean percent of morula, blastocyst and hatched blastocyst formation were significantly different between groups during a 120 hours study post hCG injection. The effect of strontium and ethanol on arrested two-cell embryos had no significant effect on the mean percentage of morula, but ethanol treatment significantly increased the percentage of blastocyst and hatched blastocyst formation compared to strontium.

Genetic inactivation of the transcription factor TIF-IA leads to nucleolar disruption, cell cycle arrest, and p53-mediated apoptosis.

PubMed

Yuan, Xuejun; Zhou, Yonggang; Casanova, Emilio; Chai, Minqiang; Kiss, Eva; Gröne, Hermann-Josef; Schütz, Günter; Grummt, Ingrid

2005-07-01

Growth-dependent regulation of rRNA synthesis is mediated by TIF-IA, a basal transcription initiation factor for RNA polymerase I. We inactivated the murine TIF-IA gene by homologous recombination in mice and embryonic fibroblasts (MEFs). TIF-IA-/- embryos die before or at embryonic day 9.5 (E9.5), displaying retardation of growth and development. In MEFs, Cre-mediated depletion of TIF-IA leads to disruption of nucleoli, cell cycle arrest, upregulation of p53, and induction of apoptosis. Elevated levels of p53 after TIF-IA depletion are due to increased binding of ribosomal proteins, such as L11, to MDM2 and decreased interaction of MDM2 with p53 and p19(ARF). RNAi-induced loss of p53 overcomes proliferation arrest and apoptosis in response to TIF-IA ablation. The striking correlation between perturbation of nucleolar function, elevated levels of p53, and induction of cell suicide supports the view that the nucleolus is a stress sensor that regulates p53 activity.

Sudden cardiac arrest following ventricular fibrillation attributed to anabolic steroid use in an adolescent.

PubMed

Lichtenfeld, Jana; Deal, Barbara J; Crawford, Susan

2016-06-01

Anabolic androgenic steroids are synthetic derivatives of testosterone that promote the growth of skeletal muscles and have many recognised cardiovascular effects. We report the clinical presentation and pathological findings of an adolescent male whose sudden cardiac arrest following ventricular fibrillation was attributed to anabolic androgenic steroid use. The age of our patient reflects the usage of anabolic androgenic steroids among younger athletes and highlights the need for increased awareness among practitioners.

Regulation of p21/CIP1/WAF-1 mediated cell-cycle arrest by RNase L and tristetraprolin, and involvement of AU-rich elements

PubMed Central

Al-Haj, Latifa; Blackshear, Perry J.; Khabar, Khalid S.A.

2012-01-01

The p21Cip1/WAF1 plays an important role in cell-cycle arrest. Here, we find that RNase L regulates p21-mediated G1 growth arrest in AU-rich elements-dependent manner. We found a significant loss of p21 mRNA expression in RNASEL−/− MEFs and that the overexpression of RNase L in HeLa cells induces p21 mRNA expression. The p21 mRNA half-life significantly changes as a result of RNase L modulation, indicating a post-transcriptional effect. Indeed, we found that RNase L promotes tristetraprolin (TTP/ZFP36) mRNA decay. This activity was not seen with dimerization- and nuclease-deficient RNase L mutants. Deficiency in TTP led to increases in p21 mRNA and protein. With induced ablation of RNase L, TTP mRNA and protein expressions were higher, while p21 expression became reduced. We further establish that TTP, but not C124R TTP mutant, binds to, and accelerates the decay of p21 mRNA. The p21 mRNA half-life was prolonged in TTP−/− MEFs. The TTP regulation of p21 mRNA decay required functional AU-rich elements. Thus, we demonstrate a novel mechanism of regulating G1 growth arrest by an RNase L-TTP-p21 axis. PMID:22718976

The transcriptional network that controls growth arrest and differentiation in a human myeloid leukemia cell line.

PubMed

Suzuki, Harukazu; Forrest, Alistair R R; van Nimwegen, Erik; Daub, Carsten O; Balwierz, Piotr J; Irvine, Katharine M; Lassmann, Timo; Ravasi, Timothy; Hasegawa, Yuki; de Hoon, Michiel J L; Katayama, Shintaro; Schroder, Kate; Carninci, Piero; Tomaru, Yasuhiro; Kanamori-Katayama, Mutsumi; Kubosaki, Atsutaka; Akalin, Altuna; Ando, Yoshinari; Arner, Erik; Asada, Maki; Asahara, Hiroshi; Bailey, Timothy; Bajic, Vladimir B; Bauer, Denis; Beckhouse, Anthony G; Bertin, Nicolas; Björkegren, Johan; Brombacher, Frank; Bulger, Erika; Chalk, Alistair M; Chiba, Joe; Cloonan, Nicole; Dawe, Adam; Dostie, Josee; Engström, Pär G; Essack, Magbubah; Faulkner, Geoffrey J; Fink, J Lynn; Fredman, David; Fujimori, Ko; Furuno, Masaaki; Gojobori, Takashi; Gough, Julian; Grimmond, Sean M; Gustafsson, Mika; Hashimoto, Megumi; Hashimoto, Takehiro; Hatakeyama, Mariko; Heinzel, Susanne; Hide, Winston; Hofmann, Oliver; Hörnquist, Michael; Huminiecki, Lukasz; Ikeo, Kazuho; Imamoto, Naoko; Inoue, Satoshi; Inoue, Yusuke; Ishihara, Ryoko; Iwayanagi, Takao; Jacobsen, Anders; Kaur, Mandeep; Kawaji, Hideya; Kerr, Markus C; Kimura, Ryuichiro; Kimura, Syuhei; Kimura, Yasumasa; Kitano, Hiroaki; Koga, Hisashi; Kojima, Toshio; Kondo, Shinji; Konno, Takeshi; Krogh, Anders; Kruger, Adele; Kumar, Ajit; Lenhard, Boris; Lennartsson, Andreas; Lindow, Morten; Lizio, Marina; Macpherson, Cameron; Maeda, Norihiro; Maher, Christopher A; Maqungo, Monique; Mar, Jessica; Matigian, Nicholas A; Matsuda, Hideo; Mattick, John S; Meier, Stuart; Miyamoto, Sei; Miyamoto-Sato, Etsuko; Nakabayashi, Kazuhiko; Nakachi, Yutaka; Nakano, Mika; Nygaard, Sanne; Okayama, Toshitsugu; Okazaki, Yasushi; Okuda-Yabukami, Haruka; Orlando, Valerio; Otomo, Jun; Pachkov, Mikhail; Petrovsky, Nikolai; Plessy, Charles; Quackenbush, John; Radovanovic, Aleksandar; Rehli, Michael; Saito, Rintaro; Sandelin, Albin; Schmeier, Sebastian; Schönbach, Christian; Schwartz, Ariel S; Semple, Colin A; Sera, Miho; Severin, Jessica; Shirahige, Katsuhiko; Simons, Cas; St Laurent, George; Suzuki, Masanori; Suzuki, Takahiro; Sweet, Matthew J; Taft, Ryan J; Takeda, Shizu; Takenaka, Yoichi; Tan, Kai; Taylor, Martin S; Teasdale, Rohan D; Tegnér, Jesper; Teichmann, Sarah; Valen, Eivind; Wahlestedt, Claes; Waki, Kazunori; Waterhouse, Andrew; Wells, Christine A; Winther, Ole; Wu, Linda; Yamaguchi, Kazumi; Yanagawa, Hiroshi; Yasuda, Jun; Zavolan, Mihaela; Hume, David A; Arakawa, Takahiro; Fukuda, Shiro; Imamura, Kengo; Kai, Chikatoshi; Kaiho, Ai; Kawashima, Tsugumi; Kawazu, Chika; Kitazume, Yayoi; Kojima, Miki; Miura, Hisashi; Murakami, Kayoko; Murata, Mitsuyoshi; Ninomiya, Noriko; Nishiyori, Hiromi; Noma, Shohei; Ogawa, Chihiro; Sano, Takuma; Simon, Christophe; Tagami, Michihira; Takahashi, Yukari; Kawai, Jun; Hayashizaki, Yoshihide

2009-05-01

Using deep sequencing (deepCAGE), the FANTOM4 study measured the genome-wide dynamics of transcription-start-site usage in the human monocytic cell line THP-1 throughout a time course of growth arrest and differentiation. Modeling the expression dynamics in terms of predicted cis-regulatory sites, we identified the key transcription regulators, their time-dependent activities and target genes. Systematic siRNA knockdown of 52 transcription factors confirmed the roles of individual factors in the regulatory network. Our results indicate that cellular states are constrained by complex networks involving both positive and negative regulatory interactions among substantial numbers of transcription factors and that no single transcription factor is both necessary and sufficient to drive the differentiation process.

Weak arrest-like and field-driven first order magnetic phase transitions of itinerant Fe3Ga4 revealed by magnetization and magnetoresistance isotherms

NASA Astrophysics Data System (ADS)

Samatham, S. Shanmukharao; Suresh, K. G.

2017-01-01

The detailed magnetic study of complex 3d-electron based Fe3Ga4 is reported. It undergoes paramagnetic to antiferromagnetic (TN) and antiferromagnetic to ferromagnetic (TC) transitions respectively around 380 and 70 K. The thermal hysteresis of field-cooled cooling (FCC) and field-cooled warming (FCW) hints at first order phase transition below Curie temperature. A weak phase coexistence of ferro and antiferromagnetic phases is suggested by exploring the arrest-like first-order phenomenon. In the intermediate temperature range, field-driven metamagnetic transition from antiferro to ferromagnetic phase is confirmed. Further bringing the system very near to TN, field-induced transitions disappear and above TN predominant paramagnetic contribution is evident. The magnetic H-T phase diagram distinguishing different magnetic phases of Fe3Ga4 is obtained.

Similar cerebral protective effectiveness of antegrade and retrograde cerebral perfusion during deep hypothermic circulatory arrest in aortic surgery: a meta-analysis of 7023 patients.

PubMed

Guo, Shasha; Sun, Yanhua; Ji, Bingyang; Liu, Jinping; Wang, Guyan; Zheng, Zhe

2015-04-01

In aortic arch surgery, deep hypothermic circulatory arrest (DHCA) combined with cerebral perfusion is employed worldwide as a routine practice. Even though antegrade cerebral perfusion (ACP) is more widely used than retrograde cerebral perfusion (RCP), the difference in benefit and risk between ACP and RCP during DHCA is uncertain. The purpose of this meta-analysis is to compare neurologic outcomes and early mortality between ACP and RCP in patients who underwent aortic surgery during DHCA. PubMed, EMBASE, and the Cochrane Library were searched using the key words "antegrade," "retrograde," "cerebral perfusion," "cardiopulmonary bypass," "extracorporeal circulation," and "cardiac surgery" for studies reporting on clinical endpoints including early mortality, stroke, temporary neurologic dysfunction (TND), and permanent neurologic dysfunction (PND) in aortic surgery requiring DHCA with ACP or RCP. Heterogeneity was analyzed with the Cochrane Q statistic and I(2) statistic. Publication bias was tested with Begg's funnel plot and Egger's test. Thirty-four studies were included in this meta-analysis, with 4262 patients undergoing DHCA + ACP and 2761 undergoing DHCA + RCP. The overall pooled relative risk for TND was 0.722 (95% CI = [0.579, 0.900]), and the z-score for overall effect was 2.9 (P = 0.004). There was low heterogeneity (I(2) = 18.7%). The analysis showed that patients undergoing DHCA + ACP had better outcomes than those undergoing DHCA + RCP in terms of TND, while there were no significant differences between groups in terms of PND, stroke, and early mortality. This meta-analysis indicates that DHCA + ACP has an advantage over DHCA + RCP in terms of TND, while the two methods show similar results in terms of PND, early mortality, and stroke. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth

PubMed Central

2013-01-01

Introduction The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs). Methods HMECs were transfected by an adenoviral system for transient overexpression of EpCAM. Thereafter, changes in cell proliferation and migration were studied using a real time measurement system. Target gene expression was evaluated by transcriptome analysis in proliferating and polarized HMEC cultures. A Chicken Chorioallantoic Membrane (CAM) xenograft model was used to study effects on in vivo growth of HMECs. Results EpCAM overexpression in HMECs did not significantly alter gene expression profile of proliferating or growth arrested cells. Proliferating HMECs displayed predominantly glycosylated EpCAM isoforms and were inhibited in cell proliferation and migration by upregulation of p27KIP1 and p53. HMECs with overexpression of EpCAM showed a down regulation of E-cadherin. Moreover, cells were more resistant to TGF-β1 induced growth arrest and maintained longer capacities to proliferate in vitro. EpCAM overexpressing HMECs xenografts in chicken embryos showed hyperplastic growth, lack of lumen formation and increased infiltrates of the chicken leukocytes. Conclusions EpCAM revealed oncogenic features in normal human breast cells by inducing resistance to TGF-β1-mediated growth arrest and supporting a cell phenotype with longer proliferative capacities in vitro. EpCAM overexpression resulted in hyperplastic growth in vivo. Thus, we suggest that EpCAM acts as a prosurvival factor counteracting terminal differentiation processes in normal mammary glands. PMID:23758908

Growth Arrest by Trehalose-6-Phosphate: An Astonishing Case of Primary Metabolite Control over Growth by Way of the SnRK1 Signaling Pathway1[C][W][OA

PubMed Central

Delatte, Thierry L.; Sedijani, Prapti; Kondou, Youichi; Matsui, Minami; de Jong, Gerhardus J.; Somsen, Govert W.; Wiese-Klinkenberg, Anika; Primavesi, Lucia F.; Paul, Matthew J.; Schluepmann, Henriette

2011-01-01

The strong regulation of plant carbon allocation and growth by trehalose metabolism is important for our understanding of the mechanisms that determine growth and yield, with obvious applications in crop improvement. To gain further insight on the growth arrest by trehalose feeding, we first established that starch-deficient seedlings of the plastidic phosphoglucomutase1 mutant were similarly affected as the wild type on trehalose. Starch accumulation in the source cotyledons, therefore, did not cause starvation and consequent growth arrest in the growing zones. We then screened the FOX collection of Arabidopsis (Arabidopsis thaliana) expressing full-length cDNAs for seedling resistance to 100 mm trehalose. Three independent transgenic lines were identified with dominant segregation of the trehalose resistance trait that overexpress the bZIP11 (for basic region/leucine zipper motif) transcription factor. The resistance of these lines to trehalose could not be explained simply through enhanced trehalase activity or through inhibition of bZIP11 translation. Instead, trehalose-6-phosphate (T6P) accumulation was much increased in bZIP11-overexpressing lines, suggesting that these lines may be insensitive to the effects of T6P. T6P is known to inhibit the central stress-integrating kinase SnRK1 (KIN10) activity. We confirmed that this holds true in extracts from seedlings grown on trehalose, then showed that two independent transgenic lines overexpressing KIN10 were insensitive to trehalose. Moreover, the expression of marker genes known to be jointly controlled by SnRK1 activity and bZIP11 was consistent with low SnRK1 or bZIP11 activity in seedlings on trehalose. These results reveal an astonishing case of primary metabolite control over growth by way of the SnRK1 signaling pathway involving T6P, SnRK1, and bZIP11. PMID:21753116

High-dose ascorbic acid induces carcinostatic effects through hydrogen peroxide and superoxide anion radical generation-induced cell death and growth arrest in human tongue carcinoma cells.

PubMed

Ohwada, Ryouhei; Ozeki, Yu; Saitoh, Yasukazu

2017-01-01

High-dose ascorbic acid (AsA) treatment, known as pharmacological AsA, has been shown to exert carcinostatic effects in many types of cancer cells and in vivo tumour models. Although pharmacological AsA has potential as a complementary and alternative medicine for anticancer treatment, its effects on human tongue carcinoma have not yet been elucidated. In this study, we investigated the effect of AsA treatment on human tongue carcinoma HSC-4 cells compared with non-tumourigenic tongue epithelial dysplastic oral keratinocyte (DOK) cells. Our results show that treatment with 1 and 3 mM of AsA for 60 min preferentially inhibits the growth of human tongue carcinoma HSC-4 over DOK cells. Furthermore, AsA-induced effects were accompanied by increased intracellular oxidative stress and were repressed by treatment with a hydrogen peroxide (H 2 O 2 ) scavenger catalase and a superoxide anion radical (O 2 - ) scavenger, tempol. Time-lapse observation and thymidine analog EdU incorporation revealed that AsA treatment induces not only cell death but also suppression of DNA synthesis and cell growth. Moreover, the growth arrest was accompanied by abnormal cellular morphologies whereby cells extended dendrite-like pseudopodia. Taken together, our results demonstrate that AsA treatment can induce carcinostatic effects through induction of cell death, growth arrest, and morphological changes mediated by H 2 O 2 and O 2 - generation. These findings suggest that high-dose AsA treatment represents an effective treatment for tongue cancer as well as for other types of cancer cells.

Expression of the bacterial type III effector DspA/E in Saccharomyces cerevisiae down-regulates the sphingolipid biosynthetic pathway leading to growth arrest.

PubMed

Siamer, Sabrina; Guillas, Isabelle; Shimobayashi, Mitsugu; Kunz, Caroline; Hall, Michael N; Barny, Marie-Anne

2014-06-27

Erwinia amylovora, the bacterium responsible for fire blight, relies on a type III secretion system and a single injected effector, DspA/E, to induce disease in host plants. DspA/E belongs to the widespread AvrE family of type III effectors that suppress plant defense responses and promote bacterial growth following infection. Ectopic expression of DspA/E in plant or in Saccharomyces cerevisiae is toxic, indicating that DspA/E likely targets a cellular process conserved between yeast and plant. To unravel the mode of action of DspA/E, we screened the Euroscarf S. cerevisiae library for mutants resistant to DspA/E-induced growth arrest. The most resistant mutants (Δsur4, Δfen1, Δipt1, Δskn1, Δcsg1, Δcsg2, Δorm1, and Δorm2) were impaired in the sphingolipid biosynthetic pathway. Exogenously supplied sphingolipid precursors such as the long chain bases (LCBs) phytosphingosine and dihydrosphingosine also suppressed the DspA/E-induced yeast growth defect. Expression of DspA/E in yeast down-regulated LCB biosynthesis and induced a rapid decrease in LCB levels, indicating that serine palmitoyltransferase (SPT), the first and rate-limiting enzyme of the sphingolipid biosynthetic pathway, was repressed. SPT down-regulation was mediated by dephosphorylation and activation of Orm proteins that negatively regulate SPT. A Δcdc55 mutation affecting Cdc55-PP2A protein phosphatase activity prevented Orm dephosphorylation and suppressed DspA/E-induced growth arrest. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Traumatic Pancreatitis: A Rare Complication of Cardiopulmonary Resuscitation.

PubMed

Aziz, Muhammad

2017-08-17

An elderly gentleman was successfully revived after undergoing cardiopulmonary resuscitation (CPR) for cardiac arrest. Post CPR, the patient developed acute pancreatitis which was likely complication of inappropriately delivered chest compressions which caused further complications and resulted in the death of the patient. This case underlines the importance of quality chest compressions that includes correct placement of hands by the operator giving chest compressions to avoid lethal injuries to the receiver.

Twisted Gastrulation as a BMP Modulator during Mammary Gland Development and Tumorigenesis

DTIC Science & Technology

2014-05-01

present at the onset of puberty , roughly 6 weeks of age, but not at later time points we began our Q-PCR analysis at this time point. Analyzing...rudimentary ductal tree that during puberty , pregnancy and lactation undergoes complex morphological changes (Hens and Wysolmerski, 2005; Hovey and Trott...proliferates and elongates into the developing fat pad forming a rudimentary tree. Development is arrested at this point until puberty . At puberty , terminal

Melatonin effects on Plasmodium life cycle: new avenues for therapeutic approach.

PubMed

Srinivasan, Venkataramanujam; Ahmad, Asma H; Mohamed, Mahaneem; Zakaria, Rahimah

2012-05-01

Malaria remains a global health problem affecting more than 515 million people all over the world including Malaysia. It is on the rise, even within unknown regions that previous to this were free of malaria. Although malaria eradication programs carried out by vector control programs are still effective, anti-malarial drugs are also used extensively for curtailing this disease. But resistance to the use of anti-malarial drugs is also increasing on a daily basis. With an increased understanding of mechanisms that cause growth, differentiation and development of malarial parasites in rodents and humans, new avenues of therapeutic approaches for controlling the growth, synchronization and development of malarial parasites are essential. Within this context, the recent discoveries related to IP3 interconnected signalling pathways, the release of Ca2+ from intracellular stores of Plasmodium, ubiquitin protease systems as a signalling pathway, and melatonin influencing the growth and differentiation of malarial parasites by its effects on these signalling pathways have opened new therapeutic avenues for arresting the growth and differentiation of malarial parasites. Indeed, the use of melatonin antagonist, luzindole, has inhibited the melatonin's effect on these signalling pathways and thereby has effectively reduced the growth and differentiation of malarial parasites. As Plasmodium has effective sensors which detect the nocturnal plasma melatonin concentrations, suppression of plasma melatonin levels with the use of bright light during the night or by anti-melatonergic drugs and by using anti-kinase drugs will help in eradicating malaria on a global level. A number of patients have been admitted with regards to the control and management of malarial growth. Patents related to the discovery of serpentine receptors on Plasmodium, essential for modulating intra parasitic melatonin levels, procedures for effective delivery of bright light to suppress plasma melatonin levels and thereby arresting the growth and elimination of malarial parasites from the blood of the host are all cited in the paper. The purpose of the paper is to highlight the importance of melatonin acting as a cue for Plasmodium faciparum growth and to discuss the ways of curbing the effects of melatonin on Plasmodium growth and for arresting its life cycle, as a method of eliminating the parasite from the host.

Mild therapeutic hypothermia in patients after out-of-hospital cardiac arrest due to acute ST-segment elevation myocardial infarction undergoing immediate percutaneous coronary intervention.

PubMed

Wolfrum, Sebastian; Pierau, Christian; Radke, Peter W; Schunkert, Heribert; Kurowski, Volkhard

2008-06-01

Mild therapeutic hypothermia (MTH) has been integrated into international resuscitation guidelines. In the majority of patients, sudden cardiac arrest is caused by myocardial infarction. This study investigated whether a combination of MTH with primary percutaneous coronary intervention (PCI) is feasible, safe, and potentially beneficial in patients after cardiac arrest due to acute myocardial infarction. Single-center observational study with a historical control group. University clinic. Thirty-three patients after cardiac arrest with ventricular fibrillation as initial rhythm and restoration of spontaneous circulation who remained unconscious at admission and presented with acute ST elevation myocardial infarction (STEMI). In 16 consecutive patients (2005-2006), MTH was initiated immediately after admission and continued during primary PCI. Seventeen consecutive patients who were treated in a similar 2-yr observation interval before implementation of MTH (2003-2004) served as a control group. Feasibility, safety, mortality, and neurologic outcome were documented. Initiation of MTH did not result in longer door-to-balloon times compared with the control group (82 vs. 85 mins), indicating that implementation of MTH did not delay the onset of primary PCI. Target temperature (32-34 degrees C) in the MTH group was reached within 4 hrs, consistent with previous trials and suggesting that primary PCI did not affect the velocity of cooling. Despite a tendency to increased bleeding complications and infections, patients treated with MTH tended to have a lower mortality after 6 months (25% vs. 35%, p = .71) and an improved neurologic outcome as determined by a Glasgow-Pittsburgh Cerebral Performance Scale score of 1 or 2 (69% vs. 47% in the control group, p = .30). MTH in combination with primary PCI is feasible and safe in patients resuscitated after cardiac arrest due to acute myocardial infarction. A combination of these therapeutic procedures should be strongly considered as standard therapy in patients after out-of-hospital cardiac arrest due to STEMI.

The Activity of Differentiation Factors Induces Apoptosis in Polyomavirus Large T-Expressing Myoblasts

PubMed Central

Fimia, Gian Maria; Gottifredi, Vanesa; Bellei, Barbara; Ricciardi, Maria Rosaria; Tafuri, Agostino; Amati, Paolo; Maione, Rossella

1998-01-01

It is commonly accepted that pathways that regulate proliferation/differentiation processes, if altered in their normal interplay, can lead to the induction of programmed cell death. In a previous work we reported that Polyoma virus Large Tumor antigen (PyLT) interferes with in vitro terminal differentiation of skeletal myoblasts by binding and inactivating the retinoblastoma antioncogene product. This inhibition occurs after the activation of some early steps of the myogenic program. In the present work we report that myoblasts expressing wild-type PyLT, when subjected to differentiation stimuli, undergo cell death and that this cell death can be defined as apoptosis. Apoptosis in PyLT-expressing myoblasts starts after growth factors removal, is promoted by cell confluence, and is temporally correlated with the expression of early markers of myogenic differentiation. The block of the initial events of myogenesis by transforming growth factor β or basic fibroblast growth factor prevents PyLT-induced apoptosis, while the acceleration of this process by the overexpression of the muscle-regulatory factor MyoD further increases cell death in this system. MyoD can induce PyLT-expressing myoblasts to accumulate RB, p21, and muscle- specific genes but is unable to induce G00 arrest. Several markers of different phases of the cell cycle, such as cyclin A, cdk-2, and cdc-2, fail to be down-regulated, indicating the occurrence of cell cycle progression. It has been frequently suggested that apoptosis can result from an unbalanced cell cycle progression in the presence of a contrasting signal, such as growth factor deprivation. Our data involve differentiation pathways, as a further contrasting signal, in the generation of this conflict during myoblast cell apoptosis. PMID:9614186

Reconstructing the regulatory circuit of cell fate determination in yeast mating response.

PubMed

Shao, Bin; Yuan, Haiyu; Zhang, Rongfei; Wang, Xuan; Zhang, Shuwen; Ouyang, Qi; Hao, Nan; Luo, Chunxiong

2017-07-01

Massive technological advances enabled high-throughput measurements of proteomic changes in biological processes. However, retrieving biological insights from large-scale protein dynamics data remains a challenging task. Here we used the mating differentiation in yeast Saccharomyces cerevisiae as a model and developed integrated experimental and computational approaches to analyze the proteomic dynamics during the process of cell fate determination. When exposed to a high dose of mating pheromone, the yeast cell undergoes growth arrest and forms a shmoo-like morphology; however, at intermediate doses, chemotropic elongated growth is initialized. To understand the gene regulatory networks that control this differentiation switch, we employed a high-throughput microfluidic imaging system that allows real-time and simultaneous measurements of cell growth and protein expression. Using kinetic modeling of protein dynamics, we classified the stimulus-dependent changes in protein abundance into two sources: global changes due to physiological alterations and gene-specific changes. A quantitative framework was proposed to decouple gene-specific regulatory modes from the growth-dependent global modulation of protein abundance. Based on the temporal patterns of gene-specific regulation, we established the network architectures underlying distinct cell fates using a reverse engineering method and uncovered the dose-dependent rewiring of gene regulatory network during mating differentiation. Furthermore, our results suggested a potential crosstalk between the pheromone response pathway and the target of rapamycin (TOR)-regulated ribosomal biogenesis pathway, which might underlie a cell differentiation switch in yeast mating response. In summary, our modeling approach addresses the distinct impacts of the global and gene-specific regulation on the control of protein dynamics and provides new insights into the mechanisms of cell fate determination. We anticipate that our integrated experimental and modeling strategies could be widely applicable to other biological systems.

Quantitative and temporal proteome analysis of butyrate-treated colorectal cancer cells.

PubMed

Tan, Hwee Tong; Tan, Sandra; Lin, Qingsong; Lim, Teck Kwang; Hew, Choy Leong; Chung, Maxey C M

2008-06-01

Colorectal cancer is one of the most common cancers in developed countries, and its incidence is negatively associated with high dietary fiber intake. Butyrate, a short-chain fatty acid fermentation by-product of fiber induces cell maturation with the promotion of growth arrest, differentiation, and/or apoptosis of cancer cells. The stimulation of cell maturation by butyrate in colonic cancer cells follows a temporal progression from the early phase of growth arrest to the activation of apoptotic cascades. Previously we performed two-dimensional DIGE to identify differentially expressed proteins induced by 24-h butyrate treatment of HCT-116 colorectal cancer cells. Herein we used quantitative proteomics approaches using iTRAQ (isobaric tags for relative and absolute quantitation), a stable isotope labeling methodology that enables multiplexing of four samples, for a temporal study of HCT-116 cells treated with butyrate. In addition, cleavable ICAT, which selectively tags cysteine-containing proteins, was also used, and the results complemented those obtained from the iTRAQ strategy. Selected protein targets were validated by real time PCR and Western blotting. A model is proposed to illustrate our findings from this temporal analysis of the butyrate-responsive proteome that uncovered several integrated cellular processes and pathways involved in growth arrest, apoptosis, and metastasis. These signature clusters of butyrate-regulated pathways are potential targets for novel chemopreventive and therapeutic drugs for treatment of colorectal cancer.

Deoxyschizandrin, Isolated from Schisandra Berries, Induces Cell Cycle Arrest in Ovarian Cancer Cells and Inhibits the Protumoural Activation of Tumour-Associated Macrophages.

PubMed

Lee, Kijun; Ahn, Ji-Hye; Lee, Kyung-Tae; Jang, Dae Sik; Choi, Jung-Hye

2018-01-15

Deoxyschizandrin, a major lignan of Schisandra berries, has been demonstrated to have various biological activities such as antioxidant, hepatoprotective, and antidiabetic effects. However, the anti-cancer effects of deoxyschizandrin are poorly characterized. In the present study, we investigated the anti-cancer effect of deoxyschizandrin on human ovarian cancer cell lines and tumour-associated macrophages (TAMs). Deoxyschizandrin induced G₀/G₁ phase cell cycle arrest and inhibited cyclin E expression in human ovarian cancer cells. Overexpression of cyclin E significantly reversed the deoxyschizandrin-induced cell growth inhibition. Interestingly, increased production of reactive oxygen species and decreased activation of Akt were observed in A2780 cells treated with deoxyschizandrin, and the antioxidant compromised the deoxyschizandrin-induced cell growth inhibition and Akt inactivation. Moreover, deoxyschizandrin-induced cell growth inhibition was markedly suppressed by Akt overexpression. In addition, deoxyschizandrin was found to inhibit the expression of the M2 phenotype markers CD163 and CD209 in TAMs, macrophages stimulated by the ovarian cancer cells. Moreover, expression and production of the tumour-promoting factors MMP-9, RANTES, and VEGF, which are highly enhanced in TAMs, was significantly suppressed by deoxyschizandrin treatment. Taken together, these data suggest that deoxyschizandrin exerts anti-cancer effects by inducing G₀/G₁ cell cycle arrest in ovarian cancer cells and reducing the protumoural phenotype of TAMs.

GLP-1 analogues for neuroprotection after out-of-hospital cardiac arrest: study protocol for a randomized controlled trial.

PubMed

Wiberg, Sebastian; Hassager, Christian; Thomsen, Jakob Hartvig; Frydland, Martin; Høfsten, Dan Eik; Engstrøm, Thomas; Køber, Lars; Schmidt, Henrik; Møller, Jacob Eifer; Kjaergaard, Jesper

2016-06-30

Attenuating the neurological damage occurring after out-of-hospital cardiac arrest is an ongoing research effort. This dual-centre study investigates the neuroprotective effects of the glucagon-like-peptide-1 analogue Exenatide administered within 4 hours from the return of spontaneous circulation to comatose patients resuscitated from out-of-hospital cardiac arrest. This pilot study will randomize a total of 120 unconscious patients with sustained return of spontaneous circulation after out-of-hospital cardiac arrest undergoing targeted temperature management in a blinded one-to-one fashion to a 6-hour and 15-minute infusion of either Exenatide or placebo. Patients are eligible for inclusion if resuscitated from cardiac arrest with randomization from 20 minutes to 240 minutes after return of spontaneous circulation. The co-primary endpoint is feasibility, defined as the initiation of treatment within the inclusion window in more than 90 % of participants, and efficacy, defined as the area under the neuron-specific enolase curve from 0 to 72 hours after admission. Secondary endpoints include all-cause mortality at 30 days and Cerebral Performance Category as well as a modified Rankin Score at 180 days. The study has been approved by the Danish National Board of Health and the local Ethics Committee and is monitored by Good Clinical Practice units. The study is currently enrolling. This paper presents the methods and planned statistical analyses used in the GLP-1 trial and aims to minimize bias and data-driven reporting of results. 1) Danish National Board of Health, EudraCT 2013-004311-45. Registered on 25 March 2014. 2) Videnskabsetisk komité C, Region Hovedstaden, No. 45728. Registered on 29 January 2014. 3) Clinicaltrial.gov, NCT02442791 . Registered on 25 of January 2015.

Randomized controlled trial of internal and external targeted temperature management methods in post- cardiac arrest patients.

PubMed

Look, Xinqi; Li, Huihua; Ng, Mingwei; Lim, Eric Tien Siang; Pothiawala, Sohil; Tan, Kenneth Boon Kiat; Sewa, Duu Wen; Shahidah, Nur; Pek, Pin Pin; Ong, Marcus Eng Hock

2018-01-01

Targeted temperature management post-cardiac arrest is currently implemented using various methods, broadly categorized as internal and external. This study aimed to evaluate survival-to-hospital discharge and neurological outcomes (Glasgow-Pittsburgh Score) of post-cardiac arrest patients undergoing internal cooling verses external cooling. A randomized controlled trial of post-resuscitation cardiac arrest patients was conducted from October 2008-September 2014. Patients were randomized to either internal or external cooling methods. Historical controls were selected matched by age and gender. Analysis using SPSS version 21.0 presented descriptive statistics and frequencies while univariate logistic regression was done using R 3.1.3. 23 patients were randomized to internal cooling and 22 patients to external cooling and 42 matched controls were selected. No significant difference was seen between internal and external cooling in terms of survival, neurological outcomes and complications. However in the internal cooling arm, there was lower risk of developing overcooling (p=0.01) and rebound hyperthermia (p=0.02). Compared to normothermia, internal cooling had higher survival (OR=3.36, 95% CI=(1.130, 10.412), and lower risk of developing cardiac arrhythmias (OR=0.18, 95% CI=(0.04, 0.63)). Subgroup analysis showed those with cardiac cause of arrest (OR=4.29, 95% CI=(1.26, 15.80)) and sustained ROSC (OR=5.50, 95% CI=(1.64, 20.39)) had better survival with internal cooling compared to normothermia. Cooling curves showed tighter temperature control for internal compared to external cooling. Internal cooling showed tighter temperature control compared to external cooling. Internal cooling can potentially provide better survival-to-hospital discharge outcomes and reduce cardiac arrhythmia complications in carefully selected patients as compared to normothermia. Copyright © 2017. Published by Elsevier Inc.

Belinostat and vincristine demonstrate mutually synergistic cytotoxicity associated with mitotic arrest and inhibition of polyploidy in a preclinical model of aggressive diffuse large B cell lymphoma.

PubMed

Havas, Aaron P; Rodrigues, Kameron B; Bhakta, Anvi; Demirjian, Joseph A; Hahn, Seongmin; Tran, Jack; Scavello, Margarethakay; Tula-Sanchez, Ana A; Zeng, Yi; Schmelz, Monika; Smith, Catharine L

2016-12-01

Diffuse Large B-cell lymphoma (DLBCL) is an aggressive malignancy that has a 60 percent 5-year survival rate, highlighting a need for new therapeutic approaches. Histone deacetylase inhibitors (HDACi) are novel therapeutics being clinically-evaluated in combination with a variety of other drugs. However, rational selection of companion therapeutics for HDACi is difficult due to their poorly-understood, cell-type specific mechanisms of action. To address this, we developed a pre-clinical model system of sensitivity and resistance to the HDACi belinostat using DLBCL cell lines. In the current study, we demonstrate that cell lines sensitive to the cytotoxic effects of HDACi undergo early mitotic arrest prior to apoptosis. In contrast, HDACi-resistant cell lines complete mitosis after a short delay and arrest in G1. To force mitotic arrest in HDACi-resistant cell lines, we used low dose vincristine or paclitaxel in combination with belinostat and observed synergistic cytotoxicity. Belinostat curtails vincristine-induced mitotic arrest and triggers a strong apoptotic response associated with downregulated MCL-1 expression and upregulated BIM expression. Resistance to microtubule targeting agents (MTAs) has been associated with their propensity to induce polyploidy and thereby increase the probability of genomic instability that enables cancer progression. Co-treatment with belinostat effectively eliminated a vincristine-induced, actively cycling polyploid cell population. Our study demonstrates that vincristine sensitizes DLBCL cells to the cytotoxic effects of belinostat and that belinostat prevents polyploidy that could cause vincristine resistance. Our findings provide a rationale for using low dose MTAs in conjunction with HDACi as a potential therapeutic strategy for treatment of aggressive DLBCL.

Safely expanding the donor pool: brain dead donors with history of temporary cardiac arrest.

PubMed

Hoyer, Dieter P; Paul, Andreas; Saner, Fuat; Gallinat, Anja; Mathé, Zoltan; Treckmann, Juergen W; Schulze, Maren; Kaiser, Gernot M; Canbay, Ali; Molmenti, Ernesto; Sotiropoulos, Georgios C

2015-06-01

Cardiac arrest (CA) in deceased organ donors can potentially be associated with ischaemic organ injury, resulting in allograft dysfunction after liver transplantation (LT). The aim of this study was to analyse the influence of cardiac arrest in liver donors. We evaluated 884 consecutive adult patients undergoing LT at our Institution from September 2003 to December 2011. Uni- and multivariable analyses was performed to identify predictive factors of outcome and survival for organs from donors with (CA donor) and without (no CA donor) a history of cardiac arrest. We identified 77 (8.7%) CA donors. Median resuscitation time was 16.5 (1-150) minutes. Allografts from CA donors had prolonged CIT (p = 0.016), were obtained from younger individuals (p < 0.001), and had higher terminal preprocurement AST and ALT (p < 0.001) than those of no CA donors. 3-month, 1-year and 5-year survival for recipients of CA donor grafts was 79%, 76% and 57% and 72.1%, 65.1% and 53% for no CA donor grafts (log rank p = 0.435). Peak AST after LT was significantly lower in CA donor organs than in no CA donor ones (886U/l vs 1321U/l; p = 0.031). Multivariable analysis identified CIT as a risk factor for both patient and graft survival in CA donors. This analysis represents the largest cohort of liver donors with a history of cardiac arrest. Reasonable selection of these donors constitutes a safe approach to the expansion of the donor pool. Rapid allocation and implantation with diminution of CIT may further improve the outcomes of livers from CA donors. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cerebral intolerance during flow arrested carotid angioplasty.

PubMed

St Louis, Myron; Park, Brian D; Dahn, Michael; Bozeman, Patricia

2012-01-01

The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.

Miro phosphorylation sites regulate Parkin recruitment and mitochondrial motility.

PubMed

Shlevkov, Evgeny; Kramer, Tal; Schapansky, Jason; LaVoie, Matthew J; Schwarz, Thomas L

2016-10-11

The PTEN-induced putative kinase 1 (PINK1)/Parkin pathway can tag damaged mitochondria and trigger their degradation by mitophagy. Before the onset of mitophagy, the pathway blocks mitochondrial motility by causing Miro degradation. PINK1 activates Parkin by phosphorylating both Parkin and ubiquitin. PINK1, however, has other mitochondrial substrates, including Miro (also called RhoT1 and -2), although the significance of those substrates is less clear. We show that mimicking PINK1 phosphorylation of Miro on S156 promoted the interaction of Parkin with Miro, stimulated Miro ubiquitination and degradation, recruited Parkin to the mitochondria, and via Parkin arrested axonal transport of mitochondria. Although Miro S156E promoted Parkin recruitment it was insufficient to trigger mitophagy in the absence of broader PINK1 action. In contrast, mimicking phosphorylation of Miro on T298/T299 inhibited PINK1-induced Miro ubiquitination, Parkin recruitment, and Parkin-dependent mitochondrial arrest. The effects of the T298E/T299E phosphomimetic were dominant over S156E substitution. We propose that the status of Miro phosphorylation influences the decision to undergo Parkin-dependent mitochondrial arrest, which, in the context of PINK1 action on other substrates, can restrict mitochondrial dynamics before mitophagy.

Miro phosphorylation sites regulate Parkin recruitment and mitochondrial motility

PubMed Central

Shlevkov, Evgeny; Kramer, Tal; Schapansky, Jason; LaVoie, Matthew J.; Schwarz, Thomas L.

2016-01-01

The PTEN-induced putative kinase 1 (PINK1)/Parkin pathway can tag damaged mitochondria and trigger their degradation by mitophagy. Before the onset of mitophagy, the pathway blocks mitochondrial motility by causing Miro degradation. PINK1 activates Parkin by phosphorylating both Parkin and ubiquitin. PINK1, however, has other mitochondrial substrates, including Miro (also called RhoT1 and -2), although the significance of those substrates is less clear. We show that mimicking PINK1 phosphorylation of Miro on S156 promoted the interaction of Parkin with Miro, stimulated Miro ubiquitination and degradation, recruited Parkin to the mitochondria, and via Parkin arrested axonal transport of mitochondria. Although Miro S156E promoted Parkin recruitment it was insufficient to trigger mitophagy in the absence of broader PINK1 action. In contrast, mimicking phosphorylation of Miro on T298/T299 inhibited PINK1-induced Miro ubiquitination, Parkin recruitment, and Parkin-dependent mitochondrial arrest. The effects of the T298E/T299E phosphomimetic were dominant over S156E substitution. We propose that the status of Miro phosphorylation influences the decision to undergo Parkin-dependent mitochondrial arrest, which, in the context of PINK1 action on other substrates, can restrict mitochondrial dynamics before mitophagy. PMID:27679849

Iron uptake controls the generation of Leishmania infective forms through regulation of ROS levels

PubMed Central

Mittra, Bidyottam; Cortez, Mauro; Haydock, Andrew; Ramasamy, Gowthaman; Myler, Peter J.

2013-01-01

During its life cycle, Leishmania undergoes extreme environmental changes, alternating between insect vectors and vertebrate hosts. Elevated temperature and decreased pH, conditions encountered after macrophage invasion, can induce axenic differentiation of avirulent promastigotes into virulent amastigotes. Here we show that iron uptake is a major trigger for the differentiation of Leishmania amazonensis amastigotes, independently of temperature and pH changes. We found that iron depletion from the culture medium triggered expression of the ferrous iron transporter LIT1 (Leishmania iron transporter 1), an increase in iron content of the parasites, growth arrest, and differentiation of wild-type (WT) promastigotes into infective amastigotes. In contrast, LIT1-null promastigotes showed reduced intracellular iron content and sustained growth in iron-poor media, followed by cell death. LIT1 up-regulation also increased iron superoxide dismutase (FeSOD) activity in WT but not in LIT1-null parasites. Notably, the superoxide-generating drug menadione or H2O2 was sufficient to trigger differentiation of WT promastigotes into fully infective amastigotes. LIT1-null promastigotes accumulated superoxide radicals and initiated amastigote differentiation after exposure to H2O2 but not to menadione. Our results reveal a novel role for FeSOD activity and reactive oxygen species in orchestrating the differentiation of virulent Leishmania amastigotes in a process regulated by iron availability. PMID:23382545

Management and complications of anaesthesia during balloon valvuloplasty for pulmonic stenosis in dogs: 39 cases (2000 to 2012).

PubMed

Ramos, R V; Monteiro-Steagall, B P; Steagall, P V M

2014-04-01

The aim of this study was to report the management and complications of anaesthesia in dogs undergoing balloon valvuloplasty. A retrospective review of medical records of dogs that were diagnosed with pulmonic stenosis and undergoing balloon valvuloplasty between 2000 and 2012. Thirty-nine cases were identified (28 males and 11 females). Median (range) age and bodyweight was 6 (4 to 48) months and 11·5 (2·0 to 30·3) kg, respectively. The most commonly represented breeds included mixed breed (n = 7, 17·9%) and English bulldog (n = 6, 15·3%). Anaesthesia was induced most commonly with intravenous administration of ketamine-diazepam (n = 8, 20·5%), propofol-diazepam (n = 8, 20·5%), or propofol-midazolam-lidocaine (n = 6, 15·4%), and maintained with isoflurane in combination with fentanyl or lidocaine. Anaesthetic and surgery times (mean ± sd) were 268·5 ±54 minutes and 193·2 ±50 minutes, respectively. The most common intraoperative complications were hypotension (n = 19, 48·7%), bradycardia (n = 8, 20·5%) and desaturation (n = 7, 17·9%). Cardiac arrhythmias were observed in 21 (53·8%) dogs. Death occurred in one (2·6%) dog due to severe hypotension after ballooning followed by cardiac arrest. Successful anaesthesia can be performed in young dogs with pulmonic stenosis undergoing balloon valvuloplasty. Management of anaesthesia requires intense monitoring and immediate treatment of complications. Anaesthetic risk increases during ballooning and may result in cardiac arrest. © 2014 British Small Animal Veterinary Association.

THE RACE/ETHNICITY DISPARITY IN MISDEMEANOR MARIJUANA ARRESTS IN NEW YORK CITY*

PubMed Central

GOLUB, ANDREW; JOHNSON, BRUCE D.; DUNLAP, ELOISE

2008-01-01

Research Summary This article examines the growth in marijuana misdemeanor arrests in New York City (NYC) from 1980 to 2003 and its differential impact on blacks and Hispanics. Since 1980, the New York City Police Department (NYPD) expanded its use of arrest and detention for minor offenses under its quality-of-life (QOL) policing initiative. Arrest data indicate that during the 1990s the primary focus of QOL policing became smoking marijuana in public view (MPV). By 2000, MPV had become the most common misdemeanor arrest, accounting for 15% of all NYC adult arrests and rivaling controlled substance arrests as the primary focus of drug abuse control. Of note, most MPV arrestees have been black or Hispanic. Furthermore, black and Hispanic MPV arrestees have been more likely to be detained prior to arraignment, convicted, and sentenced to jail than their white counterparts. Policy Implications In light of the disparities, we recommend that the NYPD consider scaling back on MPV enforcement and reducing the harshness of treatment by routinely issuing Desk Appearance Tickets when the person is not wanted on other charges, so that most MPV arrestees would not be detained. Furthermore, we recommend that legislators should consider making smoking marijuana in public a violation and not a misdemeanor. Lastly, we suggest ways that NYC could monitor the effectiveness of these policy modifications to assure that the city continues to meet its goals for order maintenance. PMID:18841246

Sarsaparilla (Smilax Glabra Rhizome) Extract Activates Redox-Dependent ATM/ATR Pathway to Inhibit Cancer Cell Growth by S Phase Arrest, Apoptosis, and Autophagy.

PubMed

She, Tiantian; Feng, Junnan; Lian, Shenyi; Li, Ruobing; Zhao, Chuanke; Song, Guoliang; Luo, Jie; Dawuti, Rouxianguli; Cai, Shaoqing; Qu, Like; Shou, Chengchao

2017-01-01

Sarsaparilla (Smilax Glabra Rhizome) exerts growth inhibitory effect on multiple cancer cells in vitro and in vivo, and redox-dependent persistent activation of ERK1/2 has been reported to underlie this effect. Here, we report an activation of ATM/ATR-dependent signaling pathway also as a mechanism for the cancer cell growth inhibition induced by the supernatant fraction of the water-soluble extract from sarsaparilla (SW). SW treatment (3.5 μg/μL) promoted the phosphorylations of ATM, ATR, and CHK1 in AGS and HT-29 cells. The ATM kinase inhibitor, KU55933, could reverse SW-induced ERK phosphorylation but not the reduced glutathione/oxidized glutathione (GSH/GSSG) imbalance in AGS cells. However, both the redox inhibitor glutathione (GSH) and ERK inhibitor U0126 antagonized SW-induced phosphorylations of ATM, ATR, and CHK1 in AGS cells. We further found KU55933 significantly antagonized SW-induced S phase arrest, apoptosis, autophagy and the resultant cell growth inhibition. Our results provide another molecular basis for the anticancer action of sarsaparilla.

H32, a non-quinone sulfone analog of vitamin K3, inhibits human hepatoma cell growth by inhibiting Cdc25 and activating ERK.

PubMed

Kar, Siddhartha; Wang, Meifang; Ham, Seung Wook; Carr, Brian I

2006-10-01

We previously synthesized a K-vitamin derivative, Cpd 5, which was a potent growth inhibitor of human tumor cells, including Hep3B hepatoma cells. However, being a quinone compound, Cpd 5 has the potential for generating toxic reactive oxygen species (ROS). We therefore synthesized a nonquinone sulfone derivative, H32, which has a sufone group substituting the quinone. The IC50 of H32 for Hep3B cells was found to be 2.5 microM, which was 2.5 and 3.2 times more potent than Cpd 5 and vitamin K3 respectively. It induced apoptosis in Hep3B cells but did not generate ROS when compared to Cpd 5. Interestingly, under similar culture conditions, normal rat hepatocytes were 14-fold more and 7-fold more resistant to the growth inhibitory effects of H32 than Hep3B and PLC/PRF5 cells respectively. H32 preferentially inhibited the activities of the cell cycle controlling Cdc25A phosphatase likely by binding to its catalytic cysteine. As a consequence, it induced inhibitory tyrosine phosphorylation of the Cdc25 substrate kinases Cdk2 and Cdk4 in Hep3B cells and the cells undergo an arrest in the G1 phase of the cell cycle. H32 also induced persistent phosphorylation of the MAPK protein ERK1/2, but marginal JNK1/2 and p38 phosphorylation. The ERK inhibitor U0126, added at least 30 min prior to H32, antagonized the growth inhibition induced by H32. However, the JNK and p38 inhibitors, JNKI-II and SB203580, were not able to antagonize H32 induced growth inhibition. Thus, H32 differentially inhibited growth of normal and liver tumor cells by preferentially inhibiting the actions of Cdc25 phosphatases and inducing persistent ERK phosphorylation.

Rapidly transported organelles containing membrane and cytoskeletal components: their relation to axonal growth

PubMed Central

1987-01-01

We have examined the movements, composition, and cellular origin of phase-dense varicosities in cultures of chick sympathetic and sensory neurons. These organelles are variable in diameter (typically between 0.2 and 2 microns) and undergo saltatory movements both towards and away from the neuronal cell body. Their mean velocities vary inversely with the size of the organelle and are greater in the retrograde than the anterograde direction. Organelles stain with the lipophilic dye 1, 1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine and with antibodies to cytoskeletal components. In cultures double-stained with antibodies to alpha-tubulin and 70-kD neurofilament protein (NF-L), approximately 40% of the organelles stain for tubulin, 30% stain for NF- L, 10% stain for both tubulin and NF-L, and 40% show no staining with either antibody. The association of cytoskeletal proteins with the organelles shows that these proteins are able to move by a form of rapid axonal transport. Under most culture conditions the predominant direction of movement is towards the cell body, suggesting that the organelles are produced at or near the growth cone. Retrograde movements continue in culture medium lacking protein or high molecular mass components and increase under conditions in which the advance of the growth cone is arrested. There is a fourfold increase in the number of organelles moving retrogradely in neurites that encounter a substratum-associated barrier to elongation; retrograde movements increase similarly in cultures exposed to cytochalasin at levels known to block growth cone advance. No previously described organelle shows behavior coordinated with axonal growth in this way. We propose that the organelles contain membrane and cytoskeletal components that have been delivered to the growth cone, by slow or fast anterograde transport, in excess of the amounts required to synthesize more axon. In view of their rapid mobility and variable contents, we suggest that they be called "neuronal parcels." PMID:3693400

c-Myc plays a key role in TADs-induced apoptosis and cell cycle arrest in human hepatocellular carcinoma cells

PubMed Central

Zhang, Dongdong; Qi, Junpeng; Liu, Rui; Dai, Bingling; Ma, Weina; Zhan, Yingzhuan; Zhang, Yanmin

2015-01-01

Cancer cell growth is complicated progression which is regulated and controlled by multiple factors including cell cycle, migration and apoptosis. In present study, we report that TADs, a novel derivative of taspine, has an essential role in resisting hepatocellular carcinoma growth (including arrest cell cycle) and migration, and inducing cell apoptosis. Our findings demonstrated that the TADs showed good inhibition on the hepatoma cell growth and migration, and good action on apoptosis induction. Using genome-wide microarray analysis, we found the down-regulated growth and apoptosis factors, and selected down-regulated genes were confirmed by Western blot. Knockdown of a checkpoint c-Myc by siRNA significantly attenuated tumor inhibition and apoptosis effects of TADs. Moreover, our results indicated TADs could simultaneously increase cyclin D1 protein levels and decrease amount of cyclin E, cyclin B1 and cdc2 of the cycle proteins, and also TADs reduced Bcl-2 expression, and upregulated Bad, Bak and Bax activities. In conclusion, these results illustrated that TADs is a key factor in growth and apoptosis signaling inhibitor, has potential in cancer therapy. PMID:26045987

Fluoxetine regulates cell growth inhibition of interferon-α.

PubMed

Lin, Yu-Min; Yu, Bu-Chin; Chiu, Wen-Tai; Sun, Hung-Yu; Chien, Yu-Chieh; Su, Hui-Chen; Yen, Shu-Yang; Lai, Hsin-Wen; Bai, Chyi-Huey; Young, Kung-Chia; Tsao, Chiung-Wen

2016-10-01

Fluoxetine, a well-known anti-depression agent, may act as a chemosensitizer to assist and promote cancer therapy. However, how fluoxetine regulates cellular signaling to enhance cellular responses against tumor cell growth remains unclear. In the present study, addition of fluoxetine promoted growth inhibition of interferon-alpha (IFN-α) in human bladder carcinoma cells but not in normal uroepithelial cells through lessening the IFN-α-induced apoptosis but switching to cause G1 arrest, and maintaining the IFN-α-mediated reduction in G2/M phase. Activations and signal transducer and transactivator (STAT)-1 and peroxisome proliferator-activated receptor alpha (PPAR-α) were involved in this process. Chemical inhibitions of STAT-1 or PPAR-α partially rescued bladder carcinoma cells from IFN-α-mediated growth inhibition via blockades of G1 arrest, cyclin D1 reduction, p53 downregulation and p27 upregulation in the presence of fluoxetine. However, the functions of both proteins were not involved in the control of fluoxetine over apoptosis and maintained the declined G2/M phase of IFN-α. These results indicated that activation of PPAR-α and STAT-1 participated, at least in part, in growth inhibition of IFN-α in the presence of fluoxetine.

Investigation Analysis of Crack Growth Arresting with Fasteners in Hybrid Laminated Skin-Stiffener Joint

NASA Astrophysics Data System (ADS)

Jeevan Kumar, N.; Ramesh Babu, P.

2018-02-01

In recent years carbon fibre-reinforced polymers (CFRP) emerged its increasing demand in aerospace engineering. Due to their high specific strength to weight ratio, these composites offer more characteristics and considerable advantages compared to metals. Metals, unlike composites, offer plasticity effects to evade high stress concentrations during postbuckling. Under compressive load, composite structures show a wide range of damage mechanisms where a set of damage modes combined together might lead to the eventual structural collapse. Crack is one of the most critical damages in fiber composites, which are being employed in primary aircraft structures. A parametric study is conducted to investigate the arrest mechanism of the delamination or crack growth with installation of multiple fasteners when the delamination is embedded in between the skin and stiffener interface.

Cerebral Oximetry During Infant Cardiac Surgery: Evaluation of and Relationship to Early Postoperative Outcome

PubMed Central

Kussman, Barry D.; Wypij, David; DiNardo, James A.; Newburger, Jane W.; Mayer, John E.; del Nido, Pedro J.; Bacha, Emile A.; Pigula, Frank; McGrath, Ellen; Laussen, Peter C.

2009-01-01

Background We examined changes in cerebral oxygen saturation during infant heart surgery and its relationship to anatomic diagnosis and early outcome Methods Regional cerebral oxygen saturation (rSO2) was measured by near-infrared spectroscopy in 104 infants undergoing biventricular repair without aortic arch obstruction as part of a randomized trial of hemodilution to a hematocrit of 25% versus 35%. Results Prior to cardiopulmonary bypass (CPB), infants with tetralogy of Fallot had higher rSO2 values compared to those with D-transposition of the great arteries (D-TGA) or ventricular septal defect (P < 0.001). During CPB cooling, low flow and at the termination of CPB, D-TGA subjects had the highest rSO2 values (P < 0.001). There were no significant associations between intraoperative rSO2 and early postoperative outcomes after adjustment for diagnosis. In 39 D-TGA subjects with ≥5 minutes of deep hypothermic circulatory arrest, there was no correlation between the rSO2 (91 ± 6%) or hematocrit (29.2 ± 5.5%) at the onset of arrest and the rate of decline in rSO2 during arrest. Conclusions Intraoperative rSO2 varies according to anatomic diagnosis but accounts for very little of the variance in early outcome. As measured by frontal near-infrared spectroscopy, higher levels of hematocrit and current perfusion techniques appear to provide an adequate oxygen reservoir prior to relatively short periods of deep hypothermic circulatory arrest. PMID:19299774

DNA damage-induced nuclear translocation of Apaf-1 is mediated by nucleoporin Nup107

PubMed Central

Jagot-Lacoussiere, Léonard; Faye, Audrey; Bruzzoni-Giovanelli, Heriberto; Villoutreix, Bruno O; Rain, Jean-Christophe; Poyet, Jean-Luc

2015-01-01

Beside its central role in the mitochondria-dependent cell death pathway, the apoptotic protease activating factor 1 (Apaf-1) is involved in the DNA damage response through cell-cycle arrest induced by genotoxic stress. This non-apoptotic function requires a nuclear translocation of Apaf-1 during the G1-to-S transition. However, the mechanisms that trigger the nuclear accumulation of Apaf-1 upon DNA damage remain to be investigated. Here we show that the main 4 isoforms of Apaf-1 can undergo nuclear translocation and restore Apaf-1 deficient MEFs cell cycle arrest in the S phase following genotoxic stress through activation of Chk-1. Interestingly, DNA damage-dependent nuclear accumulation of Apaf-1 occurs independently of p53 and the retinoblastoma (pRb) pathway. We demonstrated that Apaf-1 associates with the nucleoporin Nup107 and this association is necessary for Apaf-1 nuclear import. The CED-4 domain of Apaf-1 directly binds to the central domain of Nup107 in an ATR-regulated, phosphorylation-dependent manner. Interestingly, expression of the Apaf-1-interacting domain of Nup107 interfered with Apaf-1 nuclear translocation upon genotoxic stress, resulting in a marked reduction of Chk-1 activation and cell cycle arrest. Thus, our results confirm the crucial role of Apaf-1 nuclear relocalization in mediating cell-cycle arrest induced by genotoxic stress and implicate Nup107 as a critical regulator of the DNA damage-induced intra-S phase checkpoint response. PMID:25695197

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Huiling; Li, Ridong; Li, Li

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{submore » 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.« less

An unusual reason for severe bradycardia leading to cardiac arrest during general anaesthesia: a case report.

PubMed

Struzkova, Klara; Stourac, Petr; Kanovsky, Jan; Krikava, Ivo; Toukalkova, Michaela; Sevcik, Pavel

2014-12-01

Takotsubo cardiomyopathy also known as transient balooning syndrome is an increasingly reported phenomenon characterized by acute reversible apical or midventricular dysfunction. This stress- induced cardiomyopathy mimics myocardial infarction, but without significant coronary artery disease, and rarely presents in perioperative period. We report a case of postmenopausal woman scheduled to undergo elective cholecystectomy, with no history of coronary artery disease. She presented perioperatively with Takotsubo cardiomyopathy by unique manifestation-asystoly. This uncommon cause of cardiac arrest during anaesthesia was possibly induced by preoperative emotional stress. There was full recovery thanks to intensive management. In Takotsubo cardiomyopathy related cardiogenic shock we used the calcium sensitiser levosimendan successfully. Takotsubo cardiomyopathy has an excellent long-term prognosis and nearly all patients have full recovery of left ventricular function. We emphasize the importance of heavy premedication by stress compromised patients and the need of sufficiently deep anaesthesia and analgesia during surgeries.

Achieving Full Neurological Recovery in Snakebite using Best Supportive Care.

PubMed

Wright, Sally; Haddock, Genevieve

2018-05-14

A 29-year-old woman presented to a community hospital in Sierra Leone 2 hours after being bitten by an unknown snake. On arrival, she was agitated though alert, however deteriorated into respiratory arrest. There was no local availability of antivenom. The patient remained in respiratory arrest undergoing best supportive care in a low-resource setting for 2 hours 55 minutes before returning to spontaneous ventilation. She went on to make a full neurological recovery. Though spontaneous recovery following snakebite envenoming is rare, this case showcases that good communication and basic manoeuvres can have a hugely positive impact on patient outcome. Alongside this, it highlights the need for staff and community engagement and implementation of local protocols in order to improve confidence and achieve consistent practice. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Motion of a Distinguishable Impurity in the Bose Gas: Arrested Expansion Without a Lattice and Impurity Snaking

NASA Astrophysics Data System (ADS)

Robinson, Neil J.; Caux, Jean-Sébastien; Konik, Robert M.

2016-04-01

We consider the real-time dynamics of an initially localized distinguishable impurity injected into the ground state of the Lieb-Liniger model. Focusing on the case where integrability is preserved, we numerically compute the time evolution of the impurity density operator in regimes far from analytically tractable limits. We find that the injected impurity undergoes a stuttering motion as it moves and expands. For an initially stationary impurity, the interaction-driven formation of a quasibound state with a hole in the background gas leads to arrested expansion—a period of quasistationary behavior. When the impurity is injected with a finite center-of-mass momentum, the impurity moves through the background gas in a snaking manner, arising from a quantum Newton's cradlelike scenario where momentum is exchanged back and forth between the impurity and the background gas.

Motion of a distinguishable Impurity in the Bose gas: Arrested expansion without a lattice and impurity snaking

DOE PAGES

Neil J. Robinson; Caux, Jean -Sebastien; Konik, Robert M.

2016-04-07

We consider the real-time dynamics of an initially localized distinguishable impurity injected into the ground state of the Lieb-Liniger model. Focusing on the case where integrability is preserved, we numerically compute the time evolution of the impurity density operator in regimes far from analytically tractable limits. We find that the injected impurity undergoes a stuttering motion as it moves and expands. For an initially stationary impurity, the interaction-driven formation of a quasibound state with a hole in the background gas leads to arrested expansion—a period of quasistationary behavior. In conclusion, when the impurity is injected with a finite center-of-mass momentum,more » the impurity moves through the background gas in a snaking manner, arising from a quantum Newton’s cradlelike scenario where momentum is exchanged back and forth between the impurity and the background gas.« less

Okadaic acid mediates p53 hyperphosphorylation and growth arrest in cells with wild-type p53 but increases aberrant mitoses in cells with non-functional p53.

PubMed

Milczarek, G J; Chen, W; Gupta, A; Martinez, J D; Bowden, G T

1999-06-01

The protein phosphatase inhibitor and tumor promoting agent okadaic acid (OA), has been shown previously to induce hyperphosphorylation of p53 protein, which in turn correlated with increased transactivation or apoptotic function. However, how the tumor promotion effects of OA relate to p53 tumor supressor function (or dysfunction) remain unclear. Rat embryonic fibroblasts harboring a temperature-sensitive mouse p53 transgene were treated with 50 nM doses of OA. At the wild-type permissive temperature this treatment resulted in: (i) the hyperphosphorylation of sites within tryptic peptides of the transactivation domain of p53; (ii) an increase in p53 affinity for a p21(waf1) promotor oligonucleotide; (iii) an increase in cellular steady state levels of p21(waf1) message; (iv) a G2/M cell cycle blockage in addition to the G1/S arrest previously associated with p53; and (v) no increased incidence of apoptosis. On the other hand, OA treatment at the mutated p53 permissive temperature resulted in a relatively high incidence of aberrant mitosis with no upregulation of p21(waf1) message. These results suggest that while wild-type p53 blocks the proliferative effects of OA through p21(waf1)-mediated growth arrest, cells with non-functional p53 cannot arrest and suffer relatively high levels of OA-mediated aberrant mitoses.

Inactivation of Thioredoxin Reductases Reveals a Complex Interplay between Thioredoxin and Glutathione Pathways in Arabidopsis Development[W

PubMed Central

Reichheld, Jean-Philippe; Khafif, Mehdi; Riondet, Christophe; Droux, Michel; Bonnard, Géraldine; Meyer, Yves

2007-01-01

NADPH-dependent thioredoxin reductases (NTRs) are key regulatory enzymes determining the redox state of the thioredoxin system. The Arabidopsis thaliana genome has two genes coding for NTRs (NTRA and NTRB), both of which encode mitochondrial and cytosolic isoforms. Surprisingly, plants of the ntra ntrb knockout mutant are viable and fertile, although with a wrinkled seed phenotype, slower plant growth, and pollen with reduced fitness. Thus, in contrast with mammals, our data demonstrate that neither cytosolic nor mitochondrial NTRs are essential in plants. Nevertheless, in the double mutant, the cytosolic thioredoxin h3 is only partially oxidized, suggesting an alternative mechanism for thioredoxin reduction. Plant growth in ntra ntrb plants is hypersensitive to buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis, and thioredoxin h3 is totally oxidized under this treatment. Interestingly, this BSO-mediated growth arrest is fully reversible, suggesting that BSO induces a growth arrest signal but not a toxic accumulation of activated oxygen species. Moreover, crossing ntra ntrb with rootmeristemless1, a mutant blocked in root growth due to strongly reduced glutathione synthesis, led to complete inhibition of both shoot and root growth, indicating that either the NTR or the glutathione pathway is required for postembryonic activity in the apical meristem. PMID:17586656

Inactivation of thioredoxin reductases reveals a complex interplay between thioredoxin and glutathione pathways in Arabidopsis development.

PubMed

Reichheld, Jean-Philippe; Khafif, Mehdi; Riondet, Christophe; Droux, Michel; Bonnard, Géraldine; Meyer, Yves

2007-06-01

NADPH-dependent thioredoxin reductases (NTRs) are key regulatory enzymes determining the redox state of the thioredoxin system. The Arabidopsis thaliana genome has two genes coding for NTRs (NTRA and NTRB), both of which encode mitochondrial and cytosolic isoforms. Surprisingly, plants of the ntra ntrb knockout mutant are viable and fertile, although with a wrinkled seed phenotype, slower plant growth, and pollen with reduced fitness. Thus, in contrast with mammals, our data demonstrate that neither cytosolic nor mitochondrial NTRs are essential in plants. Nevertheless, in the double mutant, the cytosolic thioredoxin h3 is only partially oxidized, suggesting an alternative mechanism for thioredoxin reduction. Plant growth in ntra ntrb plants is hypersensitive to buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis, and thioredoxin h3 is totally oxidized under this treatment. Interestingly, this BSO-mediated growth arrest is fully reversible, suggesting that BSO induces a growth arrest signal but not a toxic accumulation of activated oxygen species. Moreover, crossing ntra ntrb with rootmeristemless1, a mutant blocked in root growth due to strongly reduced glutathione synthesis, led to complete inhibition of both shoot and root growth, indicating that either the NTR or the glutathione pathway is required for postembryonic activity in the apical meristem.

Dihydroartemisinin is an inhibitor of ovarian cancer cell growth.

PubMed

Jiao, Yang; Ge, Chun-min; Meng, Qing-hui; Cao, Jian-ping; Tong, Jian; Fan, Sai-jun

2007-07-01

To investigate the anticancer activity of dihydroartemisinin (DHA), a derivative of antimalaria drug artemisinin in a panel of human ovarian cancer cell lines. Cell growth was determined by the MTT viability assay. Apoptosis and cell cycle progression were evaluated by a DNA fragmentation gel electro-phoresis, flow cytometry assay, and TUNEL assay; protein and mRNA expression were analyzed by Western blotting and RT-PCR assay. Artemisinin and its derivatives, including artesunate, arteether, artemether, arteannuin, and DHA, exhibit anticancer growth activities in human ovarian cancer cells. Among them, DHA is the most effective in inhibiting cell growth. Ovarian cancer cell lines are more sensitive (5-10-fold) to DHA treatment compared to normal ovarian cell lines. DHA at micromolar dose levels exhibits a dose- and time-dependent cytotoxicity in ovarian cancer cell lines. Furthermore, DHA induced apoptosis and G2 cell cycle arrest, accompanied by a decrease of Bcl-xL and Bcl-2 and an increase of Bax and Bad. The promising results show for the first time that DHA inhibits the growth of human ovarian cancer cells. The selective inhibition of ovarian cancer cell growth, apoptosis induction, and G2 arrest provide in vitro evidence for further studies of DHA as a possible anticancer drug in the clinical treatment of ovarian cancer.

Nutrient-Dependent Endocycling in Steroidogenic Tissue Dictates Timing of Metamorphosis in Drosophila melanogaster

PubMed Central

Ohhara, Yuya; Kobayashi, Satoru

2017-01-01

Many animals have an intrinsic growth checkpoint during juvenile development, after which an irreversible decision is made to upregulate steroidogenesis, triggering the metamorphic juvenile-to-adult transition. However, a molecular process underlying such a critical developmental decision remains obscure. Here we show that nutrient-dependent endocycling in steroidogenic cells provides the machinery necessary for irreversible activation of metamorphosis in Drosophila melanogaster. Endocycle progression in cells of the prothoracic gland (PG) is tightly coupled with the growth checkpoint, and block of endocycle in PG cells causes larval developmental arrest due to reduction in biosynthesis of the steroid hormone ecdysone. Moreover, inhibition of the nutrient sensor target of rapamycin (TOR) in the PG during the checkpoint period causes endocycle inhibition and developmental arrest, which can be rescued by inducing additional rounds of endocycles by Cyclin E. We propose that a TOR-mediated cell cycle checkpoint in steroidogenic tissue provides a systemic growth checkpoint for reproductive maturation. PMID:28121986

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

PubMed Central

DiCarlo, Stephen E.; Reddy, Thipparthi R.

2012-01-01

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

Pib2 and the EGO complex are both required for activation of TORC1.

PubMed

Varlakhanova, Natalia V; Mihalevic, Michael J; Bernstein, Kara A; Ford, Marijn G J

2017-11-15

The TORC1 complex is a key regulator of cell growth and metabolism in Saccharomyces cerevisiae The vacuole-associated EGO complex couples activation of TORC1 to the availability of amino acids, specifically glutamine and leucine. The EGO complex is also essential for reactivation of TORC1 following rapamycin-induced growth arrest and for its distribution on the vacuolar membrane. Pib2, a FYVE-containing phosphatidylinositol 3-phosphate (PI3P)-binding protein, is a newly discovered and poorly characterized activator of TORC1. Here, we show that Pib2 is required for reactivation of TORC1 following rapamycin-induced growth arrest. Pib2 is required for EGO complex-mediated activation of TORC1 by glutamine and leucine as well as for redistribution of Tor1 on the vacuolar membrane. Therefore, Pib2 and the EGO complex cooperate to activate TORC1 and connect phosphoinositide 3-kinase (PI3K) signaling and TORC1 activity. © 2017. Published by The Company of Biologists Ltd.

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

PubMed Central

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

2013-01-01

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

Down-Regulation of p53 by Double-Stranded RNA Modulates the Antiviral Response

PubMed Central

Marques, Joao T.; Rebouillat, Dominique; Ramana, Chilakamarti V.; Murakami, Junko; Hill, Jason E.; Gudkov, Andrei; Silverman, Robert H.; Stark, George R.; Williams, Bryan R. G.

2005-01-01

p53 has been well characterized as a tumor suppressor gene, but its role in antiviral defense remains unclear. A recent report has demonstrated that p53 can be induced by interferons and is activated after vesicular stomatitis virus (VSV) infection. We observed that different nononcogenic viruses, including encephalomyocarditis virus (EMCV) and human parainfluenza virus type 3 (HPIV3), induced down-regulation of p53 in infected cells. Double-stranded RNA (dsRNA) and a mutant vaccinia virus lacking the dsRNA binding protein E3L can also induce this effect, indicating that dsRNA formed during viral infection is likely the trigger for down-regulation of p53. The mechanism of down-regulation of p53 by dsRNA relies on translation inhibition mediated by the PKR and RNase L pathways. In the absence of p53, the replication of both EMCV and HPIV3 was retarded, whereas, conversely, VSV replication was enhanced. Cell cycle analysis indicated that wild-type (WT) but not p53 knockout (KO) fibroblasts undergo an early-G1 arrest following dsRNA treatment. Moreover, in WT cells the onset of dsRNA-induced apoptosis begins after p53 levels are down-regulated, whereas p53 KO cells, which lack the early-G1 arrest, rapidly undergo apoptosis. Hence, our data suggest that the down-regulation of p53 facilitates apoptosis, thereby limiting viral replication. PMID:16103161

Preoperative dehydration increases risk of postoperative acute renal failure in colon and rectal surgery.

PubMed

Moghadamyeghaneh, Zhobin; Phelan, Michael J; Carmichael, Joseph C; Mills, Steven D; Pigazzi, Alessio; Nguyen, Ninh T; Stamos, Michael J

2014-12-01

There is limited data regarding the effects of preoperative dehydration on postoperative renal function. We sought to identify associations between hydration status before operation and postoperative acute renal failure (ARF) in patients undergoing colorectal resection. The NSQIP database was used to examine the data of patients undergoing colorectal resection from 2005 to 2011. We used preoperative blood urea nitrogen (BUN)/creatinine ratio >20 as a marker of relative dehydration. Multivariate analysis using logistic regression was performed to quantify the association of BUN/Cr ratio with ARF. We sampled 27,860 patients who underwent colorectal resection. Patients with dehydration had higher risk of ARF compared to patients with BUN/Cr <10 (AOR, 1.23; P = 0.04). Dehydration was associated with an increase in mortality of the affected patients (AOR, 2.19; P < 0.01). Postoperative complication of myocardial infarction (MI) (AOR, 1.46; P < 0.01) and cardiac arrest (AOR, 1.39; P < 0.01) was higher in dehydrated patients. Open colorectal procedures (AOR, 2.67; P = 0.01) and total colectomy procedure (AOR, 1.62; P < 0.01) had associations with ARF. Dehydration before operation is a common condition in colorectal surgery (incidence of 27.7 %). Preoperative dehydration is associated with increased rates of postoperative ARF, MI, and cardiac arrest. Hydrotherapy of patients with dehydration may decrease postoperative complications in colorectal surgery.

A Benzothiazole Derivative (5g) Induces DNA Damage And Potent G2/M Arrest In Cancer Cells.

PubMed

Hegde, Mahesh; Vartak, Supriya V; Kavitha, Chandagirikoppal V; Ananda, Hanumappa; Prasanna, Doddakunche S; Gopalakrishnan, Vidya; Choudhary, Bibha; Rangappa, Kanchugarakoppal S; Raghavan, Sathees C

2017-05-31

Chemically synthesized small molecules play important role in anticancer therapy. Several chemical compounds have been reported to damage the DNA, either directly or indirectly slowing down the cancer cell progression by causing a cell cycle arrest. Direct or indirect reactive oxygen species formation causes DNA damage leading to cell cycle arrest and subsequent cell death. Therefore, identification of chemically synthesized compounds with anticancer potential is important. Here we investigate the effect of benzothiazole derivative (5g) for its ability to inhibit cell proliferation in different cancer models. Interestingly, 5g interfered with cell proliferation in both, cell lines and tumor cells leading to significant G2/M arrest. 5g treatment resulted in elevated levels of ROS and subsequently, DNA double-strand breaks (DSBs) explaining observed G2/M arrest. Consistently, we observed deregulation of many cell cycle associated proteins such as CDK1, BCL2 and their phosphorylated form, CyclinB1, CDC25c etc. Besides, 5g treatment led to decreased levels of mitochondrial membrane potential and activation of apoptosis. Interestingly, 5g administration inhibited tumor growth in mice without significant side effects. Thus, our study identifies 5g as a potent biochemical inhibitor to induce G2/M phase arrest of the cell cycle, and demonstrates its anticancer properties both ex vivo and in vivo.

GAS5 long non-coding RNA in malignant pleural mesothelioma.

PubMed

Renganathan, Arun; Kresoja-Rakic, Jelena; Echeverry, Nohemy; Ziltener, Gabriela; Vrugt, Bart; Opitz, Isabelle; Stahel, Rolf A; Felley-Bosco, Emanuela

2014-05-23

Malignant pleural mesothelioma (MPM) is an aggressive cancer with short overall survival. Long non-coding RNAs (lncRNA) are a class of RNAs more than 200 nucleotides long that do not code for protein and are part of the 90% of the human genome that is transcribed. Earlier experimental studies in mice showed GAS5 (growth arrest specific transcript 5) gene deletion in asbestos driven mesothelioma. GAS5 encodes for a lncRNA whose function is not well known, but it has been shown to act as glucocorticoid receptor decoy and microRNA "sponge". Our aim was to investigate the possible role of the GAS5 in the growth of MPM. Primary MPM cultures grown in serum-free condition in 3% oxygen or MPM cell lines grown in serum-containing medium were used to investigate the modulation of GAS5 by growth arrest after inhibition of Hedgehog or PI3K/mTOR signalling. Cell cycle length was determined by EdU incorporation assay in doxycycline inducible short hairpinGAS5 clones generated from ZL55SPT cells. Gene expression was quantified by quantitative PCR. To investigate the GAS5 promoter, a 0.77 kb sequence was inserted into a pGL3 reporter vector and luciferase activity was determined after transfection into MPM cells. Localization of GAS5 lncRNA was identified by in situ hybridization. To characterize cells expressing GAS5, expression of podoplanin and Ki-67 was assessed by immunohistochemistry. GAS5 expression was lower in MPM cell lines compared to normal mesothelial cells. GAS5 was upregulated upon growth arrest induced by inhibition of Hedgehog and PI3K/mTOR signalling in in vitro MPM models. The increase in GAS5 lncRNA was accompanied by increased promoter activity. Silencing of GAS5 increased the expression of glucocorticoid responsive genes glucocorticoid inducible leucine-zipper and serum/glucocorticoid-regulated kinase-1 and shortened the length of the cell cycle. Drug induced growth arrest was associated with GAS5 accumulation in the nuclei. GAS5 was abundant in tumoral quiescent cells and it was correlated to podoplanin expression. The observations that GAS5 levels modify cell proliferation in vitro, and that GAS5 expression in MPM tissue is associated with cell quiescence and podoplanin expression support a role of GAS5 in MPM biology.

Defining the Role of Autophagy Kinase ULK1 Signaling in Therapeutic Response of Tuberous Sclerosis Complex to mTOR Inhibitors

DTIC Science & Technology

2014-04-01

Neurofibromatosis type 2 tumor suppressor protein, merlin, by adhesion and growth arrest stimuli. J Biol Chem 273: 7757-64. 25. Shaw, R.J...McClatchey, A.I., and Jacks, T. (1998) Localization and functional domains of the Neurofibromatosis type II tumor suppressor, merlin. Cell Growth Diff 9

A Novel Function for the nm23-Hl Gene: Overexpression in Human Breast Carcinoma Cells Leads to the Formation of Basement Membrane and Growth Arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howlett, Anthony R; Petersen, Ole W; Steeg, Patricia S

1994-01-01

We have developed a culture system using reconstituted basement membrane components in which normal human mammary epithelial cells exhibit several aspects of the development and differentiation process, including formation of acinar-like structures, production and basal deposition of basement membrane components, and production and apical secretion of sialomucins. Cell lines and cultures from human breast carcinomas failed to recapitulate this process. The data indicate the importance of cellular interactions with the basement membrane in the regulation of normal breast differentiation and, potentially, its loss in neoplasia. Our purpose was to use this assay to investigate the role of the putative metastasismore » suppressor gene nm23-H1 in mammary development and differentiation. The metastatic human breast carcinoma cell line MDA-MB-435, clones transfected with a control pCMVBamneo vector, and clones transfected with pCMVBamneo vector containing nm23-H1 complementary DNA (the latter of which exhibited a substantial reduction in spontaneous metastatic potential in vivo) were cultured within a reconstituted basement membrane. Clones were examined for formation of acinus-like spheres, deposition of basement membrane components, production of sialomucin, polarization, and growth arrest. In contrast to the parental cell line and control transfectants, MDA-MB-435 breast carcinoma cells overexpressing Nm23-H1 protein regained several aspects of the normal phenotype within reconstituted basement membrane. Nm23-H1 protein-positive cells formed organized acinus-like spheres, deposited the basement membrane components type IV collagen and, to some extent, laminin to the outside of the spheres, expressed sialomucin, and growth arrested. Growth arrest of Nm23-H1 protein-positive cells was preceded by and correlated with formation of a basement membrane, suggesting a causal relationship. The data indicate a previously unidentified cause-and-effect relationship between nm23-H1 gene expression and morphological-biosynthetic-growth aspects of breast differentiation in this model system. While the basement membrane microenvironment is capable of directing the differentiation of normal human breast cells, neoplastic transformation abrogates this relationship, suggesting that intrinsic cellular events are also critical to this process. The data identify nm23-H1 gene expression as one of these events, suggesting an important role in the modulation of cellular responsiveness to the microenvironment. The data also identify previously unknown growth inhibitory effects of nm23-H1 gene overexpression.« less

Sex determination in mammalian germ cells

PubMed Central

Spiller, Cassy M; Bowles, Josephine

2015-01-01

Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model. PMID:25791730

Visualization and Quantitative Analysis of Crack-Tip Plastic Zone in Pure Nickel

NASA Astrophysics Data System (ADS)

Kelton, Randall; Sola, Jalal Fathi; Meletis, Efstathios I.; Huang, Haiying

2018-05-01

Changes in surface morphology have long been thought to be associated with crack propagation in metallic materials. We have studied areal surface texture changes around crack tips in an attempt to understand the correlations between surface texture changes and crack growth behavior. Detailed profiling of the fatigue sample surface was carried out at short fatigue intervals. An image processing algorithm was developed to calculate the surface texture changes. Quantitative analysis of the crack-tip plastic zone, crack-arrested sites near triple points, and large surface texture changes associated with crack release from arrested locations was carried out. The results indicate that surface texture imaging enables visualization of the development of plastic deformation around a crack tip. Quantitative analysis of the surface texture changes reveals the effects of local microstructures on the crack growth behavior.

Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma

PubMed Central

Park, Junhee; Kim, Hyun-Jeong; Kim, Ki Rim; Lee, Sun Kyoung; Kim, Hyungkeun; Park, Kwang-Kyun; Chung, Won-Yoon

2017-01-01

High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer. PMID:28030842

Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma.

PubMed

Park, Junhee; Kim, Hyun-Jeong; Kim, Ki Rim; Lee, Sun Kyoung; Kim, Hyungkeun; Park, Kwang-Kyun; Chung, Won-Yoon

2017-02-07

High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer.

Stereotactic probability and variability of speech arrest and anomia sites during stimulation mapping of the language dominant hemisphere.

PubMed

Chang, Edward F; Breshears, Jonathan D; Raygor, Kunal P; Lau, Darryl; Molinaro, Annette M; Berger, Mitchel S

2017-01-01

OBJECTIVE Functional mapping using direct cortical stimulation is the gold standard for the prevention of postoperative morbidity during resective surgery in dominant-hemisphere perisylvian regions. Its role is necessitated by the significant interindividual variability that has been observed for essential language sites. The aim in this study was to determine the statistical probability distribution of eliciting aphasic errors for any given stereotactically based cortical position in a patient cohort and to quantify the variability at each cortical site. METHODS Patients undergoing awake craniotomy for dominant-hemisphere primary brain tumor resection between 1999 and 2014 at the authors' institution were included in this study, which included counting and picture-naming tasks during dense speech mapping via cortical stimulation. Positive and negative stimulation sites were collected using an intraoperative frameless stereotactic neuronavigation system and were converted to Montreal Neurological Institute coordinates. Data were iteratively resampled to create mean and standard deviation probability maps for speech arrest and anomia. Patients were divided into groups with a "classic" or an "atypical" location of speech function, based on the resultant probability maps. Patient and clinical factors were then assessed for their association with an atypical location of speech sites by univariate and multivariate analysis. RESULTS Across 102 patients undergoing speech mapping, the overall probabilities of speech arrest and anomia were 0.51 and 0.33, respectively. Speech arrest was most likely to occur with stimulation of the posterior inferior frontal gyrus (maximum probability from individual bin = 0.025), and variance was highest in the dorsal premotor cortex and the posterior superior temporal gyrus. In contrast, stimulation within the posterior perisylvian cortex resulted in the maximum mean probability of anomia (maximum probability = 0.012), with large variance in the regions surrounding the posterior superior temporal gyrus, including the posterior middle temporal, angular, and supramarginal gyri. Patients with atypical speech localization were far more likely to have tumors in canonical Broca's or Wernicke's areas (OR 7.21, 95% CI 1.67-31.09, p < 0.01) or to have multilobar tumors (OR 12.58, 95% CI 2.22-71.42, p < 0.01), than were patients with classic speech localization. CONCLUSIONS This study provides statistical probability distribution maps for aphasic errors during cortical stimulation mapping in a patient cohort. Thus, the authors provide an expected probability of inducing speech arrest and anomia from specific 10-mm 2 cortical bins in an individual patient. In addition, they highlight key regions of interindividual mapping variability that should be considered preoperatively. They believe these results will aid surgeons in their preoperative planning of eloquent cortex resection.

Growth Arrest of Epithelial Cells during Measles Virus Infection Is Caused by Upregulation of Interferon Regulatory Factor 1

PubMed Central

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

2004-01-01

Natural infection with measles virus (MeV) is initiated when the virus reaches epithelial cells in the respiratory tract, oropharynx, or conjunctivae. Human epithelial cells infected with MeV frequently show growth suppression. In this study, we investigated the possible mechanisms for this suppression. The bronchiolar epithelial cell A549 showed growth arrest in G0/G1 following MeV infection or treatment with gamma interferon (IFN-γ). IFN regulatory factor-1 (IRF-1) was upregulated during MeV infection, although A549 did not produce IFN-γ. Cells of the cervical squamous cell line SiHa persistently infected with various strains of MeV displayed slower growth than uninfected SiHa cells, although the growth rates varied depending on the MeV strain. Transfection of antisense-oriented IRF-1 cDNA released the MeV-infected SiHa cells from growth suppression. Although these infected cells did not produce IFN-γ and suppressed IFN-α/β-induced Jak1 phosphorylation, Jak1 was constitutively phosphorylated. The growth rates negatively correlated with levels of both IRF-1 expression and constitutively phosphorylated Jak1. These results indicate that MeV upregulates IRF-1 in a manner that is independent of IFN but dependent on the JAK/STAT pathway. This induction of IRF-1 appears to suppress cell growth, although the extent seems to vary among MeV strains. PMID:15078941

TOR Signaling Promotes Accumulation of BZR1 to Balance Growth with Carbon Availability in Arabidopsis.

PubMed

Zhang, Zhenzhen; Zhu, Jia-Ying; Roh, Jeehee; Marchive, Chloé; Kim, Seong-Ki; Meyer, Christian; Sun, Yu; Wang, Wenfei; Wang, Zhi-Yong

2016-07-25

For maintenance of cellular homeostasis, the actions of growth-promoting hormones must be attenuated when nutrient and energy become limiting. The molecular mechanisms that coordinate hormone-dependent growth responses with nutrient availability remain poorly understood in plants [1, 2]. The target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates nutrient and energy signaling to regulate growth and homeostasis in both animals and plants [3-7]. Here, we show that sugar signaling through TOR controls the accumulation of the brassinosteroid (BR)-signaling transcription factor BZR1, which is essential for growth promotion by multiple hormonal and environmental signals [8-11]. Starvation, caused by shifting of light-grown Arabidopsis seedlings into darkness, as well as inhibition of TOR by inducible RNAi, led to plant growth arrest and reduced expression of BR-responsive genes. The growth arrest caused by TOR inactivation was partially recovered by BR treatment and the gain-of-function mutation bzr1-1D, which causes accumulation of active forms of BZR1 [12]. Exogenous sugar promoted BZR1 accumulation and seedling growth, but such sugar effects were largely abolished by inactivation of TOR, whereas the effect of TOR inactivation on BZR1 degradation is abolished by inhibition of autophagy and by the bzr1-1D mutation. These results indicate that cellular starvation leads sequentially to TOR inactivation, autophagy, and BZR1 degradation. Such regulation of BZR1 accumulation by glucose-TOR signaling allows carbon availability to control the growth promotion hormonal programs, ensuring supply-demand balance in plant growth. Copyright © 2016 Elsevier Ltd. All rights reserved.

Terrestrosin D, a steroidal saponin from Tribulus terrestris L., inhibits growth and angiogenesis of human prostate cancer in vitro and in vivo.

PubMed

Wei, Shihu; Fukuhara, Hideo; Chen, Guang; Kawada, Chiaki; Kurabayashi, Atsushi; Furihata, Mutsuo; Inoue, Keiji; Shuin, Taro

2014-01-01

The aim of this study was to investigate whether terrestrosin D (TED) inhibits the progression of castration-resistant prostate cancer and consider its mechanism. Cell cycle, mitochondrial membrane potential (ΔΨm) and apoptosis were determined by flow cytometry. Caspase-3 activity and vascular endothelial growth factor secretion were detected by a caspase-3 assay and human vascular endothelial growth factor kit, respectively. A PC-3 xenograft mouse model was used to evaluate the anticancer effect of TED in vivo. In vitro, TED strongly suppressed the growth of prostate cancer cells and endothelial cells in a dose-dependent manner. TED induced cell cycle arrest and apoptosis in PC-3 cells and human umbilical vascular endothelial cells (HUVECs). TED-induced apoptosis did not involve the caspase pathway. TED also decreased ΔΨm in PC-3 cells and HUVECs. In vivo, TED significantly suppressed tumor growth in nude mice bearing PC-3 cells, without any overt toxicity. Immunohistochemical analysis showed TED induced apoptotic cell death and inhibited angiogenesis in xenograft tumor cells. Cell cycle arrest and induction of apoptosis in cancer cells and endothelial cells might be plausible mechanisms of actions for the observed antitumor and antiangiogenic activities of TED. © 2014 S. Karger AG, Basel.

Activity of insulin growth factors and shrimp neurosecretory organ extracts on a lepidopteran cell line.

PubMed

Hatt, P J; Liebon, C; Morinière, M; Oberlander, H; Porcheron, P

1997-01-01

Ecdysteroids, or molting hormones, have been proven to be key differentiation regulators for epidermal cells in the postembryonic development of arthropods. Regulators of cell proliferation, however, remain largely unknown. To date, no diffusible insect peptidic growth factors have been characterized. Molecules structurally related to insulin have been discovered in insects, as in other eucaryotes. We developed in vitro tests for the preliminary characterization of potential growth factors in arthropods by adapting the procedures designed to detect such factors in vertebrates to an insect cell line (IAL-PID2) established from imaginal discs of the Indian meal moth. We verified the ability of these tests to measure the proliferation of IAL-PID2 cells. We tested mammalian insulin and insulin-like growth factors (IGF-I, IGF-II). Following an arrest of cell proliferation by serum deprivation, IGF-I and IGF-II caused partial resumption of the cell cycle, evidenced by DNA synthesis. In contrast, the addition of 20-hydroxyecdysone arrested the proliferation of the IAL-PID2 cells. The cell line was then used in a test for functional characterization of potential growth factors originating from the penaeid shrimp, Penaeus vannamei. Crude extracts of neurosecretory and nervous tissues, eyestalks, and ventral neural chain compensated for serum deprivation and stimulated completion of mitosis. Arch.

Subcortical pathways serving cortical language sites: initial experience with diffusion tensor imaging fiber tracking combined with intraoperative language mapping.

PubMed

Henry, Roland G; Berman, Jeffrey I; Nagarajan, Srikantan S; Mukherjee, Pratik; Berger, Mitchel S

2004-02-01

The combination of mapping functional cortical neurons by intraoperative cortical stimulation and axonal architecture by diffusion tensor MRI fiber tracking can be used to delineate the pathways between functional regions. In this study the authors investigated the feasibility of combining these techniques to yield connectivity associated with motor speech and naming. Diffusion tensor MRI fiber tracking provides maps of axonal bundles and was combined with intraoperative mapping of eloquent cortex for a patient undergoing brain tumor surgery. Tracks from eight stimulated sites in the inferior frontal cortex including mouth motor, speech arrest, and anomia were generated from the diffusion tensor MRI data. The regions connected by the fiber tracking were compared to foci from previous functional imaging reports on language tasks. Connections were found between speech arrest, mouth motor, and anomia sites and the SMA proper and cerebral peduncle. The speech arrest and a mouth motor site were also seen to connect to the putamen via the external capsule. This is the first demonstration of delineation of subcortical pathways using diffusion tensor MRI fiber tracking with intraoperative cortical stimulation. The combined techniques may provide improved preservation of eloquent regions during neurological surgery, and may provide access to direct connectivity information between functional regions of the brain.

Subcortical pathways serving cortical language sites: initial experience with diffusion tensor imaging fiber tracking combined with intraoperative language mapping

PubMed Central

Henry, Roland G.; Berman, Jeffrey I.; Nagarajan, Srikantan S.; Mukherjee, Pratik; Berger, Mitchel S.

2014-01-01

The combination of mapping functional cortical neurons by intraoperative cortical stimulation and axonal architecture by diffusion tensor MRI fiber tracking can be used to delineate the pathways between functional regions. In this study the authors investigated the feasibility of combining these techniques to yield connectivity associated with motor speech and naming. Diffusion tensor MRI fiber tracking provides maps of axonal bundles and was combined with intraoperative mapping of eloquent cortex for a patient undergoing brain tumor surgery. Tracks from eight stimulated sites in the inferior frontal cortex including mouth motor, speech arrest, and anomia were generated from the diffusion tensor MRI data. The regions connected by the fiber tracking were compared to foci from previous functional imaging reports on language tasks. Connections were found between speech arrest, mouth motor, and anomia sites and the SMA proper and cerebral peduncle. The speech arrest and a mouth motor site were also seen to connect to the putamen via the external capsule. This is the first demonstration of delineation of subcortical pathways using diffusion tensor MRI fiber tracking with intraoperative cortical stimulation. The combined techniques may provide improved preservation of eloquent regions during neurological surgery, and may provide access to direct connectivity information between functional regions of the brain. PMID:14980564

Use of a small molecule cell cycle inhibitor to control cell growth and improve specific productivity and product quality of recombinant proteins in CHO cell cultures.

PubMed

Du, Zhimei; Treiber, David; McCarter, John D; Fomina-Yadlin, Dina; Saleem, Ramsey A; McCoy, Rebecca E; Zhang, Yuling; Tharmalingam, Tharmala; Leith, Matthew; Follstad, Brian D; Dell, Brad; Grisim, Brent; Zupke, Craig; Heath, Carole; Morris, Arvia E; Reddy, Pranhitha

2015-01-01

The continued need to improve therapeutic recombinant protein productivity has led to ongoing assessment of appropriate strategies in the biopharmaceutical industry to establish robust processes with optimized critical variables, that is, viable cell density (VCD) and specific productivity (product per cell, qP). Even though high VCD is a positive factor for titer, uncontrolled proliferation beyond a certain cell mass is also undesirable. To enable efficient process development to achieve consistent and predictable growth arrest while maintaining VCD, as well as improving qP, without negative impacts on product quality from clone to clone, we identified an approach that directly targets the cell cycle G1-checkpoint by selectively inhibiting the function of cyclin dependent kinases (CDK) 4/6 with a small molecule compound. Results from studies on multiple recombinant Chinese hamster ovary (CHO) cell lines demonstrate that the selective inhibitor can mediate a complete and sustained G0/G1 arrest without impacting G2/M phase. Cell proliferation is consistently and rapidly controlled in all recombinant cell lines at one concentration of this inhibitor throughout the production processes with specific productivities increased up to 110 pg/cell/day. Additionally, the product quality attributes of the mAb, with regard to high molecular weight (HMW) and glycan profile, are not negatively impacted. In fact, high mannose is decreased after treatment, which is in contrast to other established growth control methods such as reducing culture temperature. Microarray analysis showed major differences in expression of regulatory genes of the glycosylation and cell cycle signaling pathways between these different growth control methods. Overall, our observations showed that cell cycle arrest by directly targeting CDK4/6 using selective inhibitor compound can be utilized consistently and rapidly to optimize process parameters, such as cell growth, qP, and glycosylation profile in recombinant antibody production cultures. © 2014 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

A new indole-3-carbinol tetrameric derivative inhibits cyclin-dependent kinase 6 expression, and induces G1 cell cycle arrest in both estrogen-dependent and estrogen-independent breast cancer cell lines.

PubMed

Brandi, Giorgio; Paiardini, Mirko; Cervasi, Barbara; Fiorucci, Chiara; Filippone, Paolino; De Marco, Cinzia; Zaffaroni, Nadia; Magnani, Mauro

2003-07-15

Indole-3-carbinol (I3C), autolysis product of glucosinolates present in cruciferous vegetables, has been indicated as a promising agent in preventing the development and progression of breast cancer. I3C has been shown to inhibit the growth of human cancer cells in vitro and possesses anticarcinogenic activity in vivo. Because I3C is unstable and may be converted into many polymeric products in the digestive tract, it is not yet clear whether the biological activity observed can be attributed to I3C or some of its polymeric products. In this study we synthesized a stable I3C cyclic tetrameric derivative and investigated its effects on a panel of human breast cancer cell lines. The I3C tetramer suppressed the growth of both estrogen receptor (ER) -positive (MCF-7, 734B, and BT474) and ER-negative (BT20, MDA-MB-231, and BT539) human breast cancer cell lines, and it was found to induce G(1) cell cycle arrest in a dose-dependent manner without evidence of apoptosis, suggesting a growth arrest via a cytostatic mechanism. At the molecular level, the tetramer inhibited cyclin-dependent kinase (CDK) 6 expression and activity, induced an increase in the level of p27(kip1), and reduced the level of retinoblastoma protein expression. Contrarily to CDK6, the level of CDK4, the other kinase involved in the G(1) phase of the cell cycle, remains unchanged. Interestingly, the tetramer resulted about five times more active than I3C in suppressing the growth of human breast cancer cells. On the whole, our data suggest that the I3C tetrameric derivative is a novel lead inhibitor of breast cancer cell growth that may be a considered a new, promising therapeutic agent for both ER+ and ER- breast cancer.

Growth-inhibiting effects of taxol on human liver cancer in vitro and in nude mice

PubMed Central

Yuan, Jin Hui; Zhang, Ru Ping; Zhang, Ru Gang; Guo, Li Xia; Wang, Xing Wang; Luo, Dan; Xie, Yong; Xie, Hong

2000-01-01

AIM: To investigate the effects of taxol on SMMC-7721 human hepatoma and its mechanisms. METHODS: In vitro cell growth was assessed by trypan blue exclusion method. Experimental hepatoma model was established by seeding SMMC-7721 cells subcutaneously into Balb/c (nu/nu) nude mice. In vivo tumor growth was determined by measurement of tumor diameter with Vernier calipers. The syntheses of DNA, RNA and protein were analyzed by incorporation of 3H-thymidine, 3H-uridine and 3H-leucine respectively. Using light and electron microscopes to observe the morphological changes of cells including mitosis and apoptosis. RESULTS: Taxol was effective against SMMC-7721 human hepatoma cell growth in the ranges of 2.5 nmol/L-10 nmol/L- with mitotic arrest and apoptosis in vitro. DNA, RNA and protein syntheses in cells were also obviously suppressed by in vitro treatment of taxol for 72 h. Taxol at 2.5 nmol/L reduced 3H-thymidine uptake to about 34% of the control value (P ＜ 0.05). Increasing the dose of taxol to 20 nmol/L resulted in a greater decrease in 3H-thymidine incorporation to 60% of the control value (P ＜ 0.01). At a concentration of 20 nmol/L, the 3H-uridine and 3H-leucine uptakes were reduced to 52% (P ＜ 0.05) and 63% (P ＜ 0.01), respectively. In vivo, taxol significantly inhibited SMMC-7721 tumor growth at 10 mg/kg, i.p. once daily for 10 d. A more than 90% decrease in tumor volume was observed by day 11 (P ＜ 0.01) similarly with mitotic arrest and cell apoptosis. CONCLUSION: Taxol has a marked anticancer activity in SMMC-7721 human hepatoma both in vitro and in nude mice. Its mechanisms might be associated with mitotic arrest, subsequently, apoptosis of the hepatoma cells. No obvious toxicity was observed with in vivo administration of taxol. PMID:11819558

Lentiviral Delivery of HIV-1 Vpr Protein Induces Apoptosis in Transformed Cells

NASA Astrophysics Data System (ADS)

Stewart, Sheila A.; Poon, Betty; Jowett, Jeremy B. M.; Xie, Yiming; Chen, Irvin S. Y.

1999-10-01

Most current anticancer therapies act by inducing tumor cell stasis followed by apoptosis. HIV-1 Vpr effectively induces apoptosis of T cells after arrest of cells at a G2/M checkpoint. Here, we investigated whether this property of Vpr could be exploited for use as a potential anticancer agent. As a potentially safer alternative to transfer of genes encoding Vpr, we developed a method to efficiently introduce Vpr protein directly into cells. Vpr packaged into HIV-1 virions lacking a genome induced efficient cell cycle arrest and apoptosis. Introduction of Vpr into tumor cell lines of various tissue origin, including those bearing predisposing mutations in p53, XPA, and hMLH1, induced cell cycle arrest and apoptosis with high efficiency. Significantly, apoptosis mediated by virion-associated Vpr was more effective on rapidly dividing cells compared with slow-growing cells, thus, in concept, providing a potential differential effect between some types of tumor cells and surrounding normal cells. This model system provides a rationale and proof of concept for the development of potential cancer therapeutic agents based on the growth-arresting and apoptotic properties of Vpr.

Testing the Oregon delinquency model with 9-year follow-up of the Oregon Divorce Study.

PubMed

Forgatch, Marion S; Patterson, Gerald R; Degarmo, David S; Beldavs, Zintars G

2009-01-01

This paper presents experimental tests of the Oregon delinquency model applied within a randomized design of an at-risk sample of single mothers and their elementary school-aged sons. In the theoretical model, ineffective parenting practices and deviant peer association serve as the primary mechanisms for growth in adolescent delinquent behavior and early arrests. Multiple-method assessments of 238 mothers and sons include delinquency as measured by teacher reports and official arrest records, parenting skills measured by observations of parent-child interactions, and deviant peer association as reported by focal boys. Analyses of the 9-year follow-up data indicate that the Oregon model of parent management training significantly reduced teacher-reported delinquency and police arrests for focal boys. As hypothesized, the experiments demonstrated that improving parenting practices and reducing contacts with deviant peers served as mediating mechanisms for reducing rates of adolescent delinquency. As predicted, there was also a significant delay in the timing of police arrests for youth in the experimental as compared to the control group.

Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest?

PubMed

O'Neill, Bridie; Bilal, Haris; Mahmood, Sarah; Waterworth, Paul

2012-10-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Is it worth packing the head with ice in patients undergoing deep hypothermic circulatory arrest (DHCA)? Altogether more than 34 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question, 5 of which were animal studies, 1 was a theoretical laboratory study and 1 study looked at the ability to cool using circulating water 'jackets' in humans. There were no available human studies looking at the neurological outcome with or without topical head cooling with ice without further adjunct methods of cerebral protection. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four papers studied animals undergoing DHCA for 45 min-2 h depending on the study design, with or without packing the head with ice. The studies all demonstrated improved cerebral cooling when the head was packed with ice during DHCA. They also illustrated an improved neurological outcome, with better behavioural scores (P < 0.05), and in some, survival, when compared with animals whose heads were not packed in ice. One study examined selective head cooling with the use of packing the head with ice during rewarming after DHCA. However, they demonstrated worse neurological outcomes in these animals, possibly due to the loss of cerebral vasoregulation and cerebral oedema. One study involved a laboratory experiment showing improved cooling using circulating cool water in cryotherapy braces than by using packed ice. They extrapolated that newer devices to cool the head may improve cerebral cooling during DHCA. The final study discussed here demonstrated the use of circulating water to the head in humans undergoing pulmonary endarterectomy. They found that tympanic membrane temperatures could be maintained significantly lower than bladder or rectal temperatures when using circulating water to cool the head. We conclude that topical head cooling with ice is of use during DHCA but not during rewarming following DHCA and that it may be possible to advance topical head cooling techniques using circulating water rather than packed ice.

Interplay between cell cycle and autophagy induced by boswellic acid analog

PubMed Central

Pathania, Anup S.; Guru, Santosh K.; Kumar, Suresh; Kumar, Ashok; Ahmad, Masroor; Bhushan, Shashi; Sharma, Parduman R.; Mahajan, Priya; Shah, Bhahwal A.; Sharma, Simmi; Nargotra, Amit; Vishwakarma, Ram; Korkaya, Hasan; Malik, Fayaz

2016-01-01

In this study, we investigated the role of autophagy induced by boswellic acid analog BA145 on cell cycle progression in pancreatic cancer cells. BA145 induced robust autophagy in pancreatic cancer cell line PANC-1 and exhibited cell proliferation inhibition by inducing cells to undergo G2/M arrest. Inhibition of G2/M progression was associated with decreased expression of cyclin A, cyclin B, cyclin E, cdc2, cdc25c and CDK-1. Pre-treatment of cells with autophagy inhibitors or silencing the expression of key autophagy genes abrogated BA145 induced G2/M arrest and downregulation of cell cycle regulatory proteins. It was further observed that BA145 induced autophagy by targeting mTOR kinase (IC50 1 μM), leading to reduced expression of p-mTOR, p-p70S6K (T389), p-4EBP (T37/46) and p-S6 (S240/244). Notably, inhibition of mTOR signalling by BA145 was followed by attendant activation of AKT and its membrane translocation. Inhibition of Akt through pharmacological inhibitors or siRNAs enhanced BA145 mediated autophagy, G2/M arrest and reduced expression of G2/M regulators. Further studies revealed that BA145 arbitrated inhibition of mTOR led to the activation of Akt through IGFR/PI3k/Akt feedback loop. Intervention in IGFR/PI3k/Akt loop further depreciated Akt phosphorylation and its membrane translocation that culminates in augmented autophagy with concomitant G2/M arrest and cell death. PMID:27680387

Yield stress in amorphous solids: A mode-coupling-theory analysis

NASA Astrophysics Data System (ADS)

Ikeda, Atsushi; Berthier, Ludovic

2013-11-01

The yield stress is a defining feature of amorphous materials which is difficult to analyze theoretically, because it stems from the strongly nonlinear response of an arrested solid to an applied deformation. Mode-coupling theory predicts the flow curves of materials undergoing a glass transition and thus offers predictions for the yield stress of amorphous solids. We use this approach to analyze several classes of disordered solids, using simple models of hard-sphere glasses, soft glasses, and metallic glasses for which the mode-coupling predictions can be directly compared to the outcome of numerical measurements. The theory correctly describes the emergence of a yield stress of entropic nature in hard-sphere glasses, and its rapid growth as density approaches random close packing at qualitative level. By contrast, the emergence of solid behavior in soft and metallic glasses, which originates from direct particle interactions is not well described by the theory. We show that similar shortcomings arise in the description of the caging dynamics of the glass phase at rest. We discuss the range of applicability of mode-coupling theory to understand the yield stress and nonlinear rheology of amorphous materials.

Phase behaviour in complementary DNA-coated gold nanoparticles and fd-viruses mixtures: a numerical study.

PubMed

Chiappini, Massimiliano; Eiser, Erika; Sciortino, Francesco

2017-01-01

A new gel-forming colloidal system based on a binary mixture of fd-viruses and gold nanoparticles functionalized with complementary DNA single strands has been recently introduced. Upon quenching below the DNA melt temperature, such a system results in a highly porous gel state, that may be developed in a new functional material of tunable porosity. In order to shed light on the gelation mechanism, we introduce a model closely mimicking the experimental one and we explore via Monte Carlo simulations its equilibrium phase diagram. Specifically, we model the system as a binary mixture of hard rods and hard spheres mutually interacting via a short-range square-well attractive potential. In the experimental conditions, we find evidence of a phase separation occurring either via nucleation-and-growth or via spinodal decomposition. The spinodal decomposition leads to the formation of small clusters of bonded rods and spheres whose further diffusion and aggregation leads to the formation of a percolating network in the system. Our results are consistent with the hypothesis that the mixture of DNA-coated fd-viruses and gold nanoparticles undergoes a non-equilibrium gelation via an arrested spinodal decomposition mechanism.

Tumor cell dormancy: implications for the biology and treatment of breast cancer.

PubMed

Fehm, T; Mueller, V; Marches, R; Klein, G; Gueckel, B; Neubauer, H; Solomayer, E; Becker, S

2008-01-01

Despite progress made in the therapy of solid tumors such as breast cancer, the prognosis of patients even with small primary tumors is still limited by metastatic relapse often long after removal of the primary tumor. Therefore, it has been hypothesized that primary tumors shed tumor cells already at an early stage into the blood circulation. A subset of these disseminated tumor cells may persist in a state of so-called "dormancy". Based on cell culture and animal models, dormancy can occur at two different stages. Single dormant cells are defined as cells with a lack of proliferation and apoptosis with the cells undergoing cell cycle arrest. The micrometastasis model defines tumor cell dormancy as a state of balanced apoptosis and proliferation of micrometastasis resulting in no net increase of tumor mass. Mechanisms leading to a growth activation of dormant tumor cells and the outgrowth of manifest metastases are not completely understood. Genetic predisposition of the dormant cells as well as immunological and angiogenetic influences of the surrounding environment may contribute to this phenomenon. In this review, we summarize findings on different factors for tumor cell dormancy and potential therapeutic implications that should help to reduce metastatic relapse in cancer patients.

Research protocol for platelets in out-of-hospital cardiac arrest: an observational, case-controlled, feasibility study to assess coagulation and platelet function abnormalities with ROTEM following out-of-hospital cardiac arrest (PoHCAR).

PubMed

Skorko, Agnieszka; Thomas, Matthew; Mumford, Andrew; Johnson, Thomas; Griffiths, Elinor; Greenwood, Rosemary; Benger, Jonathan

2017-07-10

Out-of-hospital cardiac arrest (OHCA) has an annual incidence of approximately 60 000 in the UK. Less than 10% of those who receive resuscitation survive to hospital discharge. For OHCA of a presumed cardiac cause, the optimal antiplatelet therapy is currently unknown. Previous studies indicate that a procoagulopathic state exists postcardiac arrest which may contribute to the formation of thrombi and contribute to poor outcomes. However, the administration of antiplatelet therapies needs to be balanced against the increased risk of bleeding that these individuals face. This observational feasibility study will recruit 30 individuals who achieve return of spontaneous circulation post-OHCA, are admitted to a single tertiary centre over a 6-month period and meet Utstein cohort criteria (witnessed cardiac arrest, VF or pulseless VT and cardiac cause of arrest likely). Rotational thromboelastometry and platelet function assessment will be performed on hospital arrival, postemergency percutaneous coronary intervention (PCI) and 12 hours, 24 hours and 48 hours post-PCI. As a comparator, 30 individuals presenting to our institution with ST-segment elevation myocardial infarction and undergoing primary PCI will have the same blood sampling performed. Plasma samples will be retained and batch tested on completion of the study for levels of protein C, protein S, thrombin-antithrombin complex, thrombin, antithrombin, plasminogen activator inhibitor-1, plasmin-antiplasmin complex, d-dimer, platelet factor-4, P selectin, E selectin and prothrombin fragments 1 and 2. 30-day follow-up for complications will be undertaken. This study has been approved by the Wales REC 7Research Ethics Committee. The results will be submitted to peer-reviewed medical journals and suitable national and international meetings. Results will be locally disseminated via our patient and public interest group. Pre-results; ISRCTN34122839. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Xiaolan, E-mail: huxiaolan1998@yahoo.com.cn; Zhang, Xianqi; Qiu, Shuifeng

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) weremore » 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.« less

Myeloid leukemia factor 1 regulates p53 by suppressing COP1 via COP9 signalosome subunit 3.

PubMed

Yoneda-Kato, Noriko; Tomoda, Kiichiro; Umehara, Mari; Arata, Yukinobu; Kato, Jun-ya

2005-05-04

Myeloid leukemia factor 1 (MLF1) was first identified as the leukemic fusion protein NPM-MLF1 generated by the t(3;5)(q25.1;q34) chromosomal translocation. Although MLF1 expresses normally in a variety of tissues including hematopoietic stem cells and the overexpression of MLF1 correlates with malignant transformation in human cancer, little is known about how MLF1 is involved in the regulation of cell growth. Here we show that MLF1 is a negative regulator of cell cycle progression functioning upstream of the tumor suppressor p53. MLF1 induces p53-dependent cell cycle arrest in murine embryonic fibroblasts. This action requires a novel binding partner, subunit 3 of the COP9 signalosome (CSN3). A reduction in the level of CSN3 protein with small interfering RNA abrogated MLF1-induced G1 arrest and impaired the activation of p53 by genotoxic stress. Furthermore, ectopic MLF1 expression and CSN3 knockdown inversely affect the endogenous level of COP1, a ubiquitin ligase for p53. Exogenous expression of COP1 overcomes MLF1-induced growth arrest. These results indicate that MLF1 is a critical regulator of p53 and suggest its involvement in leukemogenesis through a novel CSN3-COP1 pathway.

The antibacterial peptide from Bombyx mori cecropinXJ induced growth arrest and apoptosis in human hepatocellular carcinoma cells.

PubMed

Xia, Lijie; Wu, Yanling; Ma, J I; Yang, Jianhua; Zhang, Fuchun

2016-07-01

CecropinXJ is a cationic antimicrobial peptide originally isolated from the larvae of Bombyx mori . The anticancer effect of cecropinXJ has been reported in various tumor cells, including leukemia, gastric and esophageal cancer cells. However, the activity of cecropinXJ on hepatocellular carcinoma (HCC) and its underlying mechanism have not been investigated to date. Therefore, the present study investigated the efficacy and associated mechanism of cecropinXJ in Huh-7 cells. Flow cytometric analysis was performed to determine the presence of cell cycle arrested and apoptotic cells. CecropinXJ significantly inhibited the growth of Huh-7 cells in a dose- and time-dependent manner. CecropinXJ treatment for 24 h induced S cell cycle arrest and apoptosis, in addition to loss of the mitochondrial membrane potential, in hepatoma cells. CecropinXJ induced HCC cell apoptosis by activating caspase-3 and poly(ADP-ribose) polymerase. Furthermore, cecropinXJ downregulated the expression of B-cell lymphoma 2 (Bcl-2), while upregulated the expression of Bcl-2-associated death promoter and Bcl-2-associated X protein. In conclusion, the results of the present study suggest that cecropinXJ may be an active anti-HCC agent and provide novel insights into the mechanism of cecropinXJ.

Nitric oxide is involved in the oxytetracycline-induced suppression of root growth through inhibiting hydrogen peroxide accumulation in the root meristem

NASA Astrophysics Data System (ADS)

Yu, Qing-Xiang; Ahammed, Golam Jalal; Zhou, Yan-Hong; Shi, Kai; Zhou, Jie; Yu, Yunlong; Yu, Jing-Quan; Xia, Xiao-Jian

2017-02-01

Use of antibiotic-contaminated manure in crop production poses a severe threat to soil and plant health. However, few studies have studied the mechanism by which plant development is affected by antibiotics. Here, we used microscopy, flow cytometry, gene expression analysis and fluorescent dyes to study the effects of oxytetracycline (OTC), a widely used antibiotic in agriculture, on root meristem activity and the accumulation of hydrogen peroxide (H2O2) and nitric oxide (NO) in the root tips of tomato seedlings. We found that OTC caused cell cycle arrest, decreased the size of root meristem and inhibited root growth. Interestingly, the inhibition of root growth by OTC was associated with a decline in H2O2 levels but an increase in NO levels in the root tips. Diphenyliodonium (DPI), an inhibitor of H2O2 production, showed similar effects on root growth as those of OTC. However, exogenous H2O2 partially reversed the effects on the cell cycle, meristem size and root growth. Importantly, cPTIO (the NO scavenger) and tungstate (an inhibitor of nitrate reductase) significantly increased H2O2 levels in the root tips and reversed the inhibition of root growth by OTC. Out results suggest that OTC-induced NO production inhibits H2O2 accumulation in the root tips, thus leading to cell cycle arrest and suppression of root growth.

Physeal growth arrest by excessive compression: histological, biochemical, and micro-CT observations in rabbits.

PubMed

Yoo, Won Joon; Cheon, Jung-Eun; Lee, Hye Ran; Cho, Tae-Joon; Choi, In Ho

2011-12-01

Compressive force across the growth plate may cause retardation and even arrest of physeal growth. The purpose of this study was to investigate histologic changes, metabolic changes in terms of glycosaminoglycan (GAG) concentration, and contrast-enhanced micro-computed tomography (CEMCT) findings of physeal cartilage in a rabbit model of physeal damage caused by excessive compression. Compressive forces were applied via external fixators for two weeks to the growth plates of distal femurs and proximal tibiae of right hind-legs in 8-week-old rabbits. Left hind-legs remained intact and were used as controls. Forty-four bone specimens containing growth plates of distal femurs or proximal tibiae were harvested one week (n = 12) and four weeks (n = 32) after surgery, and examined for histologic findings (H&E staining) and GAGs quantification in physeal cartilage. After incubation in an ionic contrast material for 48 hours, specimens were scanned by CEMCT, and the pixel values of physeal cartilage were measured. CEMCT showed a thin, highly attenuated line parallel to the growth plate in compressed specimens harvested at four weeks after surgery, which was found to be transversely connected trabecular bone. In these specimens, GAG content in physeal cartilage was significantly lower, and CEMCT pixel values of physeal cartilage were significantly higher than in the specimens from the contralateral control side. Excessive compressive force applied to growth plates produces altered histologic features and metabolic function in terms of decreased GAG content in physeal cartilage, changes that can be demonstrated by CEMCT.

Axl as a mediator of cellular growth and survival.

PubMed

Axelrod, Haley; Pienta, Kenneth J

2014-10-15

The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context.

The HDAC6/8/10 inhibitor TH34 induces DNA damage-mediated cell death in human high-grade neuroblastoma cell lines.

PubMed

Kolbinger, Fiona R; Koeneke, Emily; Ridinger, Johannes; Heimburg, Tino; Müller, Michael; Bayer, Theresa; Sippl, Wolfgang; Jung, Manfred; Gunkel, Nikolas; Miller, Aubry K; Westermann, Frank; Witt, Olaf; Oehme, Ina

2018-06-09

High histone deacetylase (HDAC) 8 and HDAC10 expression levels have been identified as predictors of exceptionally poor outcomes in neuroblastoma, the most common extracranial solid tumor in childhood. HDAC8 inhibition synergizes with retinoic acid treatment to induce neuroblast maturation in vitro and to inhibit neuroblastoma xenograft growth in vivo. HDAC10 inhibition increases intracellular accumulation of chemotherapeutics through interference with lysosomal homeostasis, ultimately leading to cell death in cultured neuroblastoma cells. So far, no HDAC inhibitor covering HDAC8 and HDAC10 at micromolar concentrations without inhibiting HDACs 1, 2 and 3 has been described. Here, we introduce TH34 (3-(N-benzylamino)-4-methylbenzhydroxamic acid), a novel HDAC6/8/10 inhibitor for neuroblastoma therapy. TH34 is well-tolerated by non-transformed human skin fibroblasts at concentrations up to 25 µM and modestly impairs colony growth in medulloblastoma cell lines, but specifically induces caspase-dependent programmed cell death in a concentration-dependent manner in several human neuroblastoma cell lines. In addition to the induction of DNA double-strand breaks, HDAC6/8/10 inhibition also leads to mitotic aberrations and cell-cycle arrest. Neuroblastoma cells display elevated levels of neuronal differentiation markers, mirrored by formation of neurite-like outgrowths under maintained TH34 treatment. Eventually, after long-term treatment, all neuroblastoma cells undergo cell death. The combination of TH34 with plasma-achievable concentrations of retinoic acid, a drug applied in neuroblastoma therapy, synergistically inhibits colony growth (combination index (CI) < 0.1 for 10 µM of each). In summary, our study supports using selective HDAC inhibitors as targeted antineoplastic agents and underlines the therapeutic potential of selective HDAC6/8/10 inhibition in high-grade neuroblastoma.

[Clinical practice of systemic lysis in prehospital resuscitation. Success and complication rates].

PubMed

Everding, S; Römer, S; Bohn, A; Holz, E; Lieder, F; Baumgart, P; Loyen, M; Waltenberger, J; Lebiedz, P

2015-09-01

Systemic thrombolysis was introduced as the sole prehospital treatment option in patients with cardiac arrest in the setting of acute myocardial ischemia or pulmonary embolism; however, it remains the subject of discussion. A total of 194 patients with sudden prehospital cardiac arrest were included in this retrospective case control study. Of these patients, 96 in whom circulatory arrest due to cardiac disease (pulmonary artery embolism or myocardial ischemia) was suspected underwent thrombolytic treatment and were compared to the remaining 98 patients that did not undergo thrombolytic therapy. In addition to the circumstances of circulatory arrest, the course and success of resuscitation, as well as in-hospital course (including bleeding complications), overall survival and neurological outcomes were compared. There were no significant differences between patients with or without thrombolysis in terms of the circumstances of cardiac arrest. Patients that received thrombolytic treatment were significantly younger and were more frequently treated with anticoagulants, platelet aggregation inhibitors and amiodarone. They also received higher doses of epinephrine and arrived at hospital under ongoing resuscitation significantly more frequently. A trend toward more prehospital return of spontaneous circulation (ROSC) following thrombolytic treatment was seen in the entire cohort. However, patients pre-treated with acetylsalicylic acid and heparin did not show better prehospital ROSC rates as a result of additional thrombolytic therapy. Significant differences in terms of bleeding complications or the need for blood transfusion could not be seen due to the small number of patients. The indication for systemic thrombolysis in the context of prehospital resuscitation should remain restricted to patients with clear symptoms of acute pulmonary embolism or recurrent episodes of ventricular fibrillation in the setting of acute myocardial infarction. Due to a lack of evidence, systemic thrombolysis should not be used as a treatment of last resort in younger patients with persistent ventricular fibrillation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galán-Malo, Patricia; Vela, Laura; Gonzalo, Oscar

Microtubule poisons and other anti-mitotic drugs induce tumor death but the molecular events linking mitotic arrest to cell death are still not fully understood. We have analyzed cell fate after mitotic arrest produced by the microtubule-destabilizing drug vincristine in a panel of human tumor cell lines showing different response to vincristine. In Jurkat, RPMI 8226 and HeLa cells, apoptosis was triggered shortly after vincristine-induced mitotic arrest. However, A549 cells, which express a great amount of Bcl-x{sub L} and undetectable amounts of Bak, underwent mitotic slippage prior to cell death. However, when Bcl-x{sub L} gene was silenced in A549 cells, vincristinemore » induced apoptosis during mitotic arrest. Another different behavior was found in MiaPaca2 cells, where vincristine caused death by mitotic catastrophe that switched to apoptosis when cyclin B1 degradation was prevented by proteasome inhibition. Overexpression of Bcl-x{sub L} or silencing Bax and Bak expression delayed the onset of apoptosis in Jurkat and RPMI 8226 cells, enabling mitotic slippage and endoreduplication. In HeLa cells, overexpression of Bcl-x{sub L} switched cell death from apoptosis to mitotic catastrophe. Mcl-1 offered limited protection to vincristine-induced cell death and Mcl-1 degradation was not essential for vincristine-induced death. All these results, taken together, indicate that the Bcl-x{sub L}/Bak ratio and the ability to degrade cyclin B1 determine cell fate after mitotic arrest in the different tumor cell types. Highlights: ► Vincristine induces cell death by apoptosis or mitotic catastrophe. ► Apoptosis-proficient cells die by apoptosis during mitosis upon vincristine treatment. ► p53wt apoptosis-deficient cells undergo apoptosis from a G1-like tetraploid state. ► p53mt apoptosis-deficient cells can survive and divide giving rise to 8N cells.« less

Parameters Influencing Tracheostomy Decannulation in Patients Undergoing Rehabilitation after severe Acquired Brain Injury (sABI).

PubMed

Perin, Cecilia; Meroni, Roberto; Rega, Vincenzo; Braghetto, Giacomo; Cerri, Cesare Giuseppe

2017-10-01

Introduction  Tracheostomy weaning in patients who suffered a severe acquired brain injury is often a challenge and decannulation failures are not uncommon. Objective  Our study objective is to describe the decannulation failure rate in patients undergoing rehabilitation following a severe acquired brain injury (sABI); to describe the factors associated with a successful tube weaning. Methods  We conduct a retrospective analysis of charts, consecutively retrieved considering a 3-year window. Variables analyzed were: age, sex, body mass index (BMI), Glasgow Coma Scale (GCS), cause of hospitalization (stroke, trauma, cardiac arrest), date of the pathological event, gap between the index event and the first day of hospitalization, duration of Neurorehabilitation Ward hospitalization, comorbidities, chest morphological alteration, kind of tracheostomy tube used (overall dimension, cap, fenestration), SpO2, presentation and quantification of pulmonary secretion, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), respiratory frequency and pattern, cardiac frequency, presence of spontaneous cough, cough strength, and blood gas analysis. Results  We analyzed 45 tracheostomised sABI patients following stroke, trauma, or cardiac arrest. The weaning success percentage was higher in Head Trauma patients and in patients presenting positive spontaneous cough. Failures seem to be associated with presence of secretions and anoxic brain damage. GCS seemed not related to the decannulation outcome. Conclusions  Parameters that could be used as positive predictors of weaning are: mean expiratory pressure, presence of spontaneous cough, and cough strength. Provoked cough and GCS were not predictive of weaning success.

Suppression of Akt-mediated HDAC3 expression and CDK2 T39 phosphorylation by a bichalcone analog contributes to S phase retardation of cancer cells.

PubMed

Hung, Kuang-Chen; Lin, Meng-Liang; Hsu, Shih-Wei; Lee, Chuan-Chun; Huang, Ren-Yu; Wu, Tian-Shung; Chen, Shih-Shun

2018-06-15

Targeting cell cycle regulators has been a suggested mechanism for therapeutic cancer strategies. We report here that the bichalcone analog TSWU-CD4 induces S phase arrest of human cancer cells by inhibiting the formation of cyclin A-phospho (p)-cyclin-dependent kinase 2 (CDK2, threonine [Thr] 39) complexes, independent of mutant p53 expression. Ectopic expression of CDK2 (T39E), which mimics phosphorylation of the Thr 39 residue of CDK2, partially rescues the cells from TSWU-CD4-induced S phase arrest, whereas phosphorylation-deficient CDK2 (T39A) expression regulates cell growth with significant S phase arrest and enhances TSWU-CD4-triggered S phase arrest. Decreased histone deacetylase 3 (HDAC3) expression after TSWU-CD4 treatment was demonstrated, and TSWU-CD4 induced S phase arrest and inhibitory effects on cyclin A expression and CDK2 Thr 39 phosphorylation, while cyclin A-p-CDK2 (Thr 39) complex formation was suppressed by ectopic wild-type HDAC3 expression. The co-transfection of CDK2 (T39E) along with HDAC3 completely restored cyclin A expression, Thr 39-phosphorylated CDK2, cyclin A-p-CDK2 (Thr 39) complex formation, and the S phase population to normal levels. Protein kinase B (Akt) inactivation was required for TSWU-CD4-induced S phase cell cycle arrest, because constitutively active Akt1 blocks the induction of S phase arrest and the suppression of cyclin A and HDAC3 expression, CDK2 Thr 39 phosphorylation, and cyclin A-p-CDK2 (Thr 39) complex formation by TSWU-CD4. Taken together, our results indicate that TSWU-CD4 induces S phase arrest by inhibiting Akt-mediated HDAC3 expression and CDK2 Thr 39 phosphorylation to suppress the formation of cyclin A-p-CDK2 (Thr 39) complexes. Copyright © 2018 Elsevier B.V. All rights reserved.

Snipper, an Eri1 homologue, affects histone mRNA abundance and is crucial for normal Drosophila melanogaster development.

PubMed

Alexiadis, Anastasios; Delidakis, Christos; Kalantidis, Kriton

2017-07-01

The conserved 3'-5' RNA exonuclease ERI1 is implicated in RNA interference inhibition, 5.8S rRNA maturation and histone mRNA maturation and turnover. The single ERI1 homologue in Drosophila melanogaster Snipper (Snp) is a 3'-5' exonuclease, but its in vivo function remains elusive. Here, we report Snp requirement for normal Drosophila development, since its perturbation leads to larval arrest and tissue-specific downregulation results in abnormal tissue development. Additionally, Snp directly interacts with histone mRNA, and its depletion results in drastic reduction in histone transcript levels. We propose that Snp protects the 3'-ends of histone mRNAs and upon its absence, histone transcripts are readily degraded. This in turn may lead to cell cycle delay or arrest, causing growth arrest and developmental perturbations. © 2017 Federation of European Biochemical Societies.

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

2016-08-05

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.

The antioxidant transcription factor Nrf2 negatively regulates autophagy and growth arrest induced by the anticancer redox agent mitoquinone.

PubMed

Rao, V Ashutosh; Klein, Sarah R; Bonar, Spencer J; Zielonka, Jacek; Mizuno, Naoko; Dickey, Jennifer S; Keller, Paul W; Joseph, Joy; Kalyanaraman, Balaraman; Shacter, Emily

2010-11-05

Mitoquinone (MitoQ) is a synthetically modified, redox-active ubiquinone compound that accumulates predominantly in mitochondria. We found that MitoQ is 30-fold more cytotoxic to breast cancer cells than to healthy mammary cells. MitoQ treatment led to irreversible inhibition of clonogenic growth of breast cancer cells through a combination of autophagy and apoptotic cell death mechanisms. Relatively limited cytotoxicity was seen with the parent ubiquinone coenzyme Q(10.) Inhibition of cancer cell growth by MitoQ was associated with G(1)/S cell cycle arrest and phosphorylation of the checkpoint kinases Chk1 and Chk2. The possible role of oxidative stress in MitoQ activity was investigated by measuring the products of hydroethidine oxidation. Increases in ethidium and dihydroethidium levels, markers of one-electron oxidation of hydroethidine, were observed at cytotoxic concentrations of MitoQ. Keap1, an oxidative stress sensor protein that regulates the antioxidant transcription factor Nrf2, underwent oxidation, degradation, and dissociation from Nrf2 in MitoQ-treated cells. Nrf2 protein levels, nuclear localization, and transcriptional activity also increased following MitoQ treatment. Knockdown of Nrf2 caused a 2-fold increase in autophagy and an increase in G(1) cell cycle arrest in response to MitoQ but had no apparent effect on apoptosis. The Nrf2-regulated enzyme NQO1 is partly responsible for controlling the level of autophagy. Keap1 and Nrf2 act as redox sensors for oxidative perturbations that lead to autophagy. MitoQ and similar compounds should be further evaluated for novel anticancer activity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Jing; Du, Yi-Fang; Xiao, Zhi-Yi

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 decreasesmore » 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.« less

Lappaol F, a novel anticancer agent isolated from plant arctium Lappa L.

PubMed

Sun, Qing; Liu, Kanglun; Shen, Xiaoling; Jin, Weixin; Jiang, Lingyan; Sheikh, M Saeed; Hu, Yingjie; Huang, Ying

2014-01-01

In an effort to search for new cancer-fighting therapeutics, we identified a novel anticancer constituent, Lappaol F, from plant Arctium Lappa L. Lappaol F suppressed cancer cell growth in a time- and dose-dependent manner in human cancer cell lines of various tissue types. We found that Lappaol F induced G(1) and G(2) cell-cycle arrest, which was associated with strong induction of p21 and p27 and reduction of cyclin B1 and cyclin-dependent kinase 1 (CDK1). Depletion of p21 via genetic knockout or short hairpin RNA (shRNA) approaches significantly abrogated Lappaol F-mediated G(2) arrest and CDK1 and cyclin B1 suppression. These results suggest that p21 seems to play a crucial role in Lappaol F-mediated regulation of CDK1 and cyclin B1 and G(2) arrest. Lappaol F-mediated p21 induction was found to occur at the mRNA level and involved p21 promoter activation. Lappaol F was also found to induce cell death in several cancer cell lines and to activate caspases. In contrast with its strong growth inhibitory effects on tumor cells, Lappaol F had minimal cytotoxic effects on nontumorigenic epithelial cells tested. Importantly, our data also demonstrate that Lappaol F exhibited strong growth inhibition of xenograft tumors in nude mice. Lappaol F was well tolerated in treated animals without significant toxicity. Taken together, our results, for the first time, demonstrate that Lappaol F exhibits antitumor activity in vitro and in vivo and has strong potential to be developed as an anticancer therapeutic.

SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Tae Rim; Lee, Hee Min; Lee, So Yong

Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confersmore » resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.« less

Vlasov Simulation Study of Landau Damping Near the Persisting to Arrested Transition

NASA Astrophysics Data System (ADS)

Vinas, A. F.; Klimas, A. J.; Araneda, J. A.

2017-12-01

A 1-D electrostatic filtered Vlasov-Poisson simulation study is discussed. The transition from persisting to arrested Landau damping that is produced by increasing the strength of a sinusoidal perturbation on a background Vlasov-Poisson equilibrium is explored. Emphasis is placed on observed features of the electron phase-space distribution when the perturbation strength is near the transition value. A single ubiquitous waveform is found perturbing the space-averaged phase space distribution at almost any time in all of the simulations; the sole exception is the saturation stage that can occur at the end of the arrested damping scenario. This waveform contains relatively strong, very narrow structures in velocity bracketing ±vres - the velocities at which electrons must move to traverse the dominant field mode wavelength in one of its oscillation periods - and propagating with ±vres respectively. Local streams of electrons are found in these structures crossing the resonant velocities from low speed to high speed during Landau damping and from high speed to low speed during Landau growth. At the arrest time, when the field strength is briefly constant, these streams vanish. It is conjectured that the expected transfer of energy between electrons and field during Landau growth or damping has been visualized for the first time. No evidence is found in the phase-space distribution to support recent well established discoveries of a second order phase transition in the electric field evolution. While trapping is known to play a role for larger perturbation strengths, it is shown that trapping plays no role at any time in any of the simulations near the transition perturbation strength.

Insights into the Virulence Traits of Streptococcus mutans in Dentine Carious Lesions of Children with Early Childhood Caries.

PubMed

Bezerra, Daniela S; Stipp, Rafael N; Neves, Beatriz G; Guedes, Sarah F F; Nascimento, Marcelle M; Rodrigues, Lidiany K A

2016-01-01

Streptococcus mutans is an oral bacterium considered to play a major role in the development of dental caries. This study aimed to investigate the prevalence of S. mutans in active and arrested dentine carious lesions of children with early childhood caries and to examine the expression profile of selected S. mutans genes associated with survival and virulence, within the same carious lesions. Dentine samples were collected from 29 active and 16 arrested carious lesions that were diagnosed in preschool children aged 2-5 years. Total RNA was extracted from the dentine samples, and reverse transcription quantitative real-time PCR analyses were performed for the quantification of S. mutans and for analyses of the expression of S. mutans genes associated with bacterial survival (atpD, nox, pdhA) and virulence (fabM and aguD). There was no statistically significant difference in the prevalence of S. mutans between active and arrested carious lesions. Expression of the tested genes was detected in both types of carious dentine. The pdhA (p = 0.04) and aguD (p = 0.05) genes were expressed at higher levels in arrested as compared to active lesions. Our findings revealed that S. mutans is part of the viable microbial community in active and arrested dentine carious lesions. The increase in expression of the pdhA and aguD genes in arrested lesions is likely due to the unfavourable environmental conditions for microbial growth, inherent to this type of lesions. © 2016 S. Karger AG, Basel.

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

PubMed Central

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

2017-01-01

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

Functional repression of PtSND2 represses growth and development by disturbing auxin biosynthesis, transport and signaling in transgenic poplar.

PubMed

Wang, Haihai; Tang, Renjie; Wang, Cuiting; Qi, Qi; Gai, Ying; Jiang, Xiangning; Zhang, Hongxia

2015-01-01

Using chimeric repressor silencing technology, we previously reported that functional repression of PtSND2 severely arrested wood formation in transgenic poplar (Populus). Here, we provide further evidence that auxin biosynthesis, transport and signaling were disturbed in these transgenic plants, leading to pleiotropic defects in their growth patterns, including inhibited leaf enlargement and vascular tissue development in the leaf central vein, suppressed cambial growth and fiber elongation in the stem, and arrested growth in the root system. Two transgenic lines, which displayed the most remarkable phenotypic deviation from the wild-type, were selected for detailed studies. In both transgenic lines, expression of genes for auxin biosynthesis, transport and signaling was down-regulated, and indole-3-acetic acid distribution was severely disturbed in the apical buds, leaves, stems and roots of field-grown transgenic plants. Transient transcription dual-luciferase assays of ProPtTYDC2::LUC, ProPttLAX2::LUC and ProPoptrIAA20.2::LUC in poplar protoplasts revealed that expression of auxin-related genes might be regulated by PtSND2 at the transcriptional level. All these results indicate that functional repression of PtSND2 altered auxin biosynthesis, transport and signaling, and thereby disturbed the normal growth and development of transgenic plants. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Curcumin suppresses cell growth and invasion and induces apoptosis by down-regulation of Skp2 pathway in glioma cells

PubMed Central

Su, Jingna; Ma, Renqiang; Yin, Xuyuan; Zhou, Xiuxia; Li, Huabin; Wang, Zhiwei

2015-01-01

Studies have demonstrated that curcumin exerts its tumor suppressor function in a variety of human cancers including glioma. However, the exact underlying molecular mechanisms remain obscure. Emerging evidence has revealed that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in tumorigenesis. Therefore, we aim to determine whether curcumin suppresses the Skp2 expression, leading to the inhibition of cell growth, invasion, induction of apoptosis, and cell cycle arrest. To this end, we conducted multiple methods such as MTT assay, Flow cytometry, Wound healing assay, invasion assay, RT-PCR, Western blotting, and transfection to explore the functions and molecular insights of curcumin in glioma cells. We found that curcumin significantly inhibited cell growth, suppressed cell migration and invasion, induced apoptosis and cell cycle arrest in glioma cells. Furthermore, we observed that overexpression of Skp2 promoted cell growth, migration, and invasion, whereas depletion of Skp2 suppressed cell growth, migration, and invasion and triggered apoptosis in glioma cells. Mechanistically, we defined that curcumin markedly down-regulated Skp2 expression and subsequently up-regulated p57 expression. Moreover, our results demonstrated that curcumin exerts its antitumor activity through inhibition of Skp2 pathway. Collectively, our findings suggest that targeting Skp2 by curcumin could be a promising therapeutic approach for glioma prevention and therapy. PMID:26046466

Education Matters, February 2009

ERIC Educational Resources Information Center

Beckner, Gary, Ed.

2009-01-01

"Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Arrested Development: Time for Professional Development…

Tunicamycin inhibits progression of glioma cells through downregulation of the MEG-3-regulated wnt/β-catenin signaling pathway.

PubMed

Li, Xin; Xue, Lei; Peng, Qin

2018-06-01

Glioma is derived from the oncogenic transformation of brain and spinal cord glial cells, and is one of the most common primary brain tumors. Tunicamycin (TUN) can significantly inhibit glioma growth and aggressiveness by promoting apoptosis in glioma cells. The purpose of the present study was to investigate the effects of TUN on growth of glioma cells and examine the TUN-mediated signaling pathway. The inhibitory effects of TUN on apoptosis, growth, aggressiveness and cell cycle arrest of glioma tumor cells were determined by western blotting, reverse transcription-quantitative polymerase chain reaction, apoptotic assays and immunofluorescence. The results demonstrated that treatment with TUN suppressed growth, migration and invasion of glioma carcinoma cells. In addition, TUN treatment induced apoptosis of glioma cells through downregulation of Bcl-2 and P53 expression levels. Findings also indicated that TUN suppressed proliferation and arrested the glioma cells in the S phase of the cell cycle. Further analysis of the mechanisms of TUN demonstrated that TUN treatment upregulated the expression levels of maternally expressed gene (MEG)-3, wnt and β-catenin in glioma cells. Furthermore, knockdown of MEG-3 expression reversed the TUN-decreased wnt/β-catenin signaling pathway, which subsequently also reversed the TUN-inhibited growth and aggressiveness of glioma cells. In conclusion, the findings in the present study indicated that TUN treatment inhibited growth and aggressiveness through MEG-3-mediated wnt/β-catenin signaling, suggesting that TUN may be an efficient anticancer agent for the treatment of glioma.

The chemistry of caries: remineralization and demineralization events with direct clinical relevance.

PubMed

González-Cabezas, Carlos

2010-07-01

Dental caries is a site-specific disease that undergoes many cycles of demineralization and remineralization during lesion development. Because of its developmental characteristics dynamics, the caries lesion can be arrested and even repaired at its early stages without operative intervention by increasing the net mineral gain during the demineralization and remineralization cycles. This result can be accomplished by reducing the effect of etiological factors such as cariogenic biofilms and diet, and increasing the efficacy of remineralizing agents such as saliva and fluoride. Copyright 2010 Elsevier Inc. All rights reserved.

DNA SYNTHETIC RATES AND CHROMOSOME REPLICATION IN GENERATING MARROW CELLS,

DTIC Science & Technology

The normally dividing bone marrow cells of the domestic cat provede suitable material for the examination of DNA replication patterns in individual chromosomes. Autoradiographic studies of chromosomes labeled with tritiated thymidine indicate a direct relation of chromosome size to duration of DNA synthetic activity of the 10 hours of the S period studied. In this same period dividing cells achieved a maximum labeling of 80%. This suggests that a portion of the normally dividing cell population undergoes an arrest of considerable length in the G2 period. (Author)

Organic Glasses with Tunable Liquid-Crystalline Order

NASA Astrophysics Data System (ADS)

Teerakapibal, Rattavut; Huang, Chengbin; Gujral, Ankit; Ediger, Mark D.; Yu, Lian

2018-02-01

Liquid crystals (LCs) are known to undergo rapid ordering transitions with virtually no hysteresis. We report a remarkable counterexample, itraconazole, where the nematic to smectic transition is avoided at a cooling rate exceeding 20 K /s . The smectic order trapped in a glass is the order reached by the equilibrium liquid before the kinetic arrest of the end-over-end molecular rotation. This is attributed to the fact that smectic ordering requires orientational ordering and suggests a general condition for preparing organic glasses with tunable LC order for electronic applications.

Exploring the Hypersensitivity of PTEN Deleted Prostate Cancer Stem Cells to WEE1 Tyrosine Kinase Inhibitors

DTIC Science & Technology

2015-12-01

enter replica- tive senescence or undergo mitotic arrest in the presence of broken chromosomes and shortened telomeres (25–27). However, cancer cells...Cell death during crisis is mediated by mitotic telomere deprotection. Nature, 522, 492–496. 27. Herbig,U., Jobling,W.A., Chen,B.P., Chen,D.J. and...Sedivy,J.M. (2004) Telomere shortening triggers senescence of human cells through a pathway involving ATM, p53, and p21(CIP1), but not p16(INK4a).Mol

Aminomethylphosphonic Acid and Methoxyacetic Acid Induce Apoptosis in Prostate Cancer Cells

PubMed Central

Parajuli, Keshab R.; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2015-01-01

Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer. PMID:26006246

Effects of environmental factors on perinatal outcome: neurological development in cases of intrauterine growth retardation and school performance of children perinatally exposed to ionizing radiation.

PubMed Central

Ikenoue, T; Ikeda, T; Ibara, S; Otake, M; Schull, W J

1993-01-01

We performed two studies to investigate environmental factors in relation to neurological development in infants. The first, a field study, examined the elementary school performance of 929 children who were born from mothers exposed to the atomic bombing of Hiroshima, Japan, August 6, 1945. The most severe mental retardation was observed in the group exposed between 8 and 15 weeks following fertilization, and the second most severely damaged group was exposed between 16 and 25 weeks. The second, a clinical investigation, examined infants in the perinatal center who survived intrauterine growth retardation (IUGR). Those who survived with abnormal neurological development had a mean growth arrest corresponding to a uterine height of 27 weeks of gestation. This was at an earlier stage than those who survived with normal neurological development and had a mean growth arrest corresponding to 29-30 weeks of gestation. A smaller head circumference at birth was closely correlated with abnormal neurological sequelae. These results indicate that the brain development of the fetuses may have been affected by neurotoxic events similar to ionizing radiation. We emphasize the importance of avoiding neurotoxic stress to pregnant women when the fetus is in the critical period of neuronal development, before 27 weeks of gestational age. PMID:8243407

Aminomethylphosphonic acid and methoxyacetic acid induce apoptosis in prostate cancer cells.

PubMed

Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2015-05-22

Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.

Paclitaxel sensitivity of breast cancer cells requires efficient mitotic arrest and disruption of Bcl-xL/Bak interaction.

PubMed

Flores, M Luz; Castilla, Carolina; Ávila, Rainiero; Ruiz-Borrego, Manuel; Sáez, Carmen; Japón, Miguel A

2012-06-01

Taxanes are being used for the treatment of breast cancer. However, cancer cells frequently develop resistance to these drugs with the subsequent recurrence of the tumor. MDA-MB-231 and T-47D breast cancer cell lines were used to assess the effect of paclitaxel treatment on apoptosis and cell cycle, the possible mechanisms of paclitaxel resistance as well as the enhancement of paclitaxel-induced apoptosis based on its combination with phenylethyl isothiocyanate (PEITC). T-47D cells undergo apoptosis in response to paclitaxel treatment. The induction of apoptosis was associated with a robust mitotic arrest and the disruption of Bcl-xL/Bak interaction. By contrary, MDA-MB-231 cells were insensitive to paclitaxel-induced apoptosis and this was associated with a high percentage of cells that slip out of paclitaxel-imposed mitotic arrest and also with the maintenance of Bcl-xL/Bak interaction. The sequential treatment of MDA-MB-231 cells with PEITC followed by paclitaxel inhibited the slippage induced by paclitaxel and increased the apoptosis induction achieved with any of the drugs alone. In breast cancer tissues, high Bcl-xL expression was correlated with a shorter time of disease-free survival in patients treated with a chemotherapeutic regimen that contains paclitaxel, in a statistically significant way. Thus, resistance to paclitaxel in MDA-MB-231 cells is related to the inability to disrupt the Bcl-xL/Bak interaction and increased slippage. In this context, the combination of a drug that induces a strong mitotic arrest, such as paclitaxel, with another that inhibits slippage, such as PEITC, translates into increased apoptotic induction.

Prophylactic antibiotics are associated with a lower incidence of pneumonia in cardiac arrest survivors treated with targeted temperature management.

PubMed

Gagnon, David J; Nielsen, Niklas; Fraser, Gilles L; Riker, Richard R; Dziodzio, John; Sunde, Kjetil; Hovdenes, Jan; Stammet, Pascal; Friberg, Hans; Rubertsson, Sten; Wanscher, Michael; Seder, David B

2015-07-01

Prophylactic antibiotics (PRO) reduce the incidence of early-onset pneumonia in comatose patients with structural brain injury, but have not been examined in cardiac arrest survivors undergoing targeted temperature management (TTM). We investigated the effect of PRO on the development of pneumonia in that population. We conducted a retrospective cohort study comparing patients treated with PRO to those not receiving PRO (no-PRO) using Northern Hypothermia Network registry data. Cardiac arrest survivors ≥ 18 years of age with a GCS<8 at hospital admission and treated with TTM at 32-34 °C were enrolled in the registry. Differences were analyzed in univariate analyses and with logistic regression models to evaluate independent associations of clinical factors with incidence of pneumonia and good functional outcome. 416 of 1240 patients (33.5%) received PRO. Groups were similar in age, gender, arrest location, initial rhythm, and time from collapse to return of spontaneous circulation. PRO patients had less pneumonia (12.6% vs. 54.9%, p < 0.001) and less sepsis (1.2 vs. 5.7%, p < 0.001) compared to no-PRO patients. ICU length of stay (98 vs. 100 h, p = 0.2) and incidence of a good functional outcome (41.1 vs. 36.6%, p = 0.19) were similar between groups. Backwards stepwise logistic regression demonstrated PRO were independently associated with a lower incidence of pneumonia (OR 0.09, 95% 0.06-0.14, p < 0.001) and a similar incidence of good functional outcome. Prophylactic antibiotics were associated with a reduced incidence of pneumonia but a similar rate of good functional outcome. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Characteristics and clinical assessment of unexplained sudden cardiac arrest in the real-world setting: focus on idiopathic ventricular fibrillation

PubMed Central

Waldmann, Victor; Bougouin, Wulfran; Karam, Nicole; Dumas, Florence; Sharifzadehgan, Ardalan; Gandjbakhch, Estelle; Algalarrondo, Vincent; Narayanan, Kumar; Zhao, Alexandre; Amet, Denis; Jost, Daniel; Geri, Guillaume; Lamhaut, Lionel; Beganton, Frankie; Ludes, Bertrand; Bruneval, Patrick; Plu, Isabelle; Hidden-Lucet, Françoise; Albuisson, Juliette; Lavergne, Thomas; Piot, Olivier; Alonso, Christine; Leenhardt, Antoine; Lellouche, Nicolas; Extramiana, Fabrice; Cariou, Alain; Jouven, Xavier; Marijon, Eloi

2018-01-01

Abstract Aims Recent studies have shown that in more than half of apparently unexplained sudden cardiac arrests (SCA), a specific aetiology can be unmasked by a careful evaluation. The characteristics and the extent to which such cases undergo a systematic thorough investigation in real-life practice are unknown. Methods and results Data were analysed from an ongoing study, collecting all cases of out-of-hospital cardiac arrest in Paris area. Investigations performed during the index hospitalization or planned after discharge were gathered to evaluate the completeness of assessment of unexplained SCA. Between 2011 and 2016, among the 18 622 out-of-hospital cardiac arrests, 717 survivors (at hospital discharge) fulfilled the definition of cardiac SCA. Of those, 88 (12.3%) remained unexplained after electrocardiogram, echocardiography, and coronary angiography. Cardiac magnetic resonance imaging yielded the diagnosis in 25 (3.5%) cases, other investigations accounted for 14 (2.4%) additional diagnoses, and 49 (6.8%) patients were labelled as idiopathic ventricular fibrillation (IVF) (48.7 ± 15 years, 69.4% male). Among those labelled IVF, only 8 (16.3%) cases benefited from a complete workup (including pharmacological testing). Younger patients [odds ratio (OR) 6.00, 95% confidence interval (CI) 1.80–22.26] and those admitted to university centres (OR 3.60, 95% CI 1.12–12.45) were more thoroughly investigated. Genetic testing and family screening were initiated in only 9 (18.4%) and 12 (24.5%) cases, respectively. Conclusion Our findings suggest that complete investigations are carried out in a very low proportion of unexplained SCA. Standardized, systematic approaches need to be implemented to ensure that opportunities for specific therapies and preventive strategies (including relatives) are not missed. PMID:29566157

Characteristics and clinical assessment of unexplained sudden cardiac arrest in the real-world setting: focus on idiopathic ventricular fibrillation.

PubMed

Waldmann, Victor; Bougouin, Wulfran; Karam, Nicole; Dumas, Florence; Sharifzadehgan, Ardalan; Gandjbakhch, Estelle; Algalarrondo, Vincent; Narayanan, Kumar; Zhao, Alexandre; Amet, Denis; Jost, Daniel; Geri, Guillaume; Lamhaut, Lionel; Beganton, Frankie; Ludes, Bertrand; Bruneval, Patrick; Plu, Isabelle; Hidden-Lucet, Françoise; Albuisson, Juliette; Lavergne, Thomas; Piot, Olivier; Alonso, Christine; Leenhardt, Antoine; Lellouche, Nicolas; Extramiana, Fabrice; Cariou, Alain; Jouven, Xavier; Marijon, Eloi

2018-06-01

Recent studies have shown that in more than half of apparently unexplained sudden cardiac arrests (SCA), a specific aetiology can be unmasked by a careful evaluation. The characteristics and the extent to which such cases undergo a systematic thorough investigation in real-life practice are unknown. Data were analysed from an ongoing study, collecting all cases of out-of-hospital cardiac arrest in Paris area. Investigations performed during the index hospitalization or planned after discharge were gathered to evaluate the completeness of assessment of unexplained SCA. Between 2011 and 2016, among the 18 622 out-of-hospital cardiac arrests, 717 survivors (at hospital discharge) fulfilled the definition of cardiac SCA. Of those, 88 (12.3%) remained unexplained after electrocardiogram, echocardiography, and coronary angiography. Cardiac magnetic resonance imaging yielded the diagnosis in 25 (3.5%) cases, other investigations accounted for 14 (2.4%) additional diagnoses, and 49 (6.8%) patients were labelled as idiopathic ventricular fibrillation (IVF) (48.7 ± 15 years, 69.4% male). Among those labelled IVF, only 8 (16.3%) cases benefited from a complete workup (including pharmacological testing). Younger patients [odds ratio (OR) 6.00, 95% confidence interval (CI) 1.80-22.26] and those admitted to university centres (OR 3.60, 95% CI 1.12-12.45) were more thoroughly investigated. Genetic testing and family screening were initiated in only 9 (18.4%) and 12 (24.5%) cases, respectively. Our findings suggest that complete investigations are carried out in a very low proportion of unexplained SCA. Standardized, systematic approaches need to be implemented to ensure that opportunities for specific therapies and preventive strategies (including relatives) are not missed.

Outcomes after surgical pulmonary embolectomy for acute submassive and massive pulmonary embolism: A single-center experience.

PubMed

Pasrija, Chetan; Kronfli, Anthony; Rouse, Michael; Raithel, Maxwell; Bittle, Gregory J; Pousatis, Sheelagh; Ghoreishi, Mehrdad; Gammie, James S; Griffith, Bartley P; Sanchez, Pablo G; Kon, Zachary N

2018-03-01

Ideal treatment strategies for submassive and massive pulmonary embolism remain unclear. Recent reports of surgical pulmonary embolectomy have demonstrated improved outcomes, but surgical technique and postoperative outcomes continue to be refined. The aim of this study is to describe in-hospital survival and right ventricular function after surgical pulmonary embolectomy for submassive and massive pulmonary embolism with excessive predicted mortality (≥5%). All patients undergoing surgical pulmonary embolectomy (2011-2015) were retrospectively reviewed. Patients with pulmonary embolism were stratified as submassive, massive without arrest, and massive with arrest. Submassive was defined as normotensive with right ventricular dysfunction. Massive was defined as prolonged hypotension due to the pulmonary embolism. Preoperative demographics, intraoperative variables, and postoperative outcomes were compared. A total of 55 patients were identified: 28 as submassive, 18 as massive without arrest, and 9 as massive with arrest. All patients had a right ventricle/left ventricle ratio greater than 1.0. Right ventricular dysfunction decreased from moderate preoperatively to none before discharge (P < .001). In-hospital and 1-year survival were 93% and 91%, respectively, with 100% survival in the submassive group. No patients developed renal failure requiring hemodialysis at discharge or had a postoperative stroke. In this single institution experience, surgical pulmonary embolectomy is a safe and effective therapy to treat patients with a submassive or massive pulmonary embolism. Although survival in this study is higher than previously reported for patients treated with medical therapy alone, a prospective trial comparing surgical therapy with medical therapy is necessary to further elucidate the role of surgical pulmonary embolectomy in the treatment of pulmonary embolism. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Racial disparity in cardiac procedures and mortality among long-term survivors of cardiac arrest.

PubMed

Groeneveld, Peter W; Heidenreich, Paul A; Garber, Alan M

2003-07-22

It is unknown whether white and black Medicare beneficiaries have different rates of cardiac procedure utilization or long-term survival after cardiac arrest. A total of 5948 elderly Medicare beneficiaries (5429 white and 519 black) were identified who survived to hospital discharge between 1990 and 1999 after admission for cardiac arrest. Demographic, socioeconomic, and clinical information about these patients was obtained from Medicare administrative files, the US census, and the American Hospital Association's annual institutional survey. A Cox proportional hazard model that included demographic and clinical predictors indicated a hazard ratio for mortality of 1.30 (95% CI 1.09 to 1.55) for blacks aged 66 to 74 years compared with whites of the same age. The addition of cardiac procedures to this model lowered the hazard ratio for blacks to 1.23 (95% CI 1.03 to 1.46). In analyses stratified by race, implantable cardioverter-defibrillators (ICDs) had a mortality hazard ratio of 0.53 (95% CI 0.45 to 0.62) for white patients and 0.50 (95% CI 0.27 to 0.91) for black patients. Logistic regression models that compared procedure rates between races indicated odds ratios for blacks aged 66 to 74 years of 0.58 (95% CI 0.36 to 0.94) to receive an ICD and 0.50 (95% CI 0.34 to 0.75) to receive either revascularization or an ICD. There is racial disparity in long-term mortality among elderly cardiac arrest survivors. Both black and white patients benefited from ICD implantation, but blacks were less likely to undergo this potentially life-saving procedure. Lower rates of cardiac procedures may explain in part the lower survival rates among black patients.

Serial Plasma Choline Measurements after Cardiac Arrest in Patients Undergoing Mild Therapeutic Hypothermia: A Prospective Observational Pilot Trial

PubMed Central

Storm, Christian; Danne, Oliver; Ueland, Per Magne; Leithner, Christoph; Hasper, Dietrich; Schroeder, Tim

2013-01-01

Objective Choline is related to phospholipid metabolism and is a marker for global ischaemia with a small reference range in healthy volunteers. The aim of our study was to characterize the early kinetics of plasma free choline in patients after cardiac arrest. Additionally, we investigated the potential of plasma free choline to predict neurological outcome. Methods Twenty patients admitted to our medical intensive care unit were included in this prospective, observational trial. All patients were enrolled between May 2010 and May 2011. They received post cardiac arrest treatment including mild therapeutic hypothermia which was initiated with a combination of cold fluid and a feedback surface cooling device according to current guidelines. Sixteen blood samples per patient were analysed for plasma free choline levels within the first week after resuscitation. Choline was detected by liquid chromatography-tandem mass spectrometry. Results Most patients showed elevated choline levels on admission (median 14.8 µmol/L; interquartile range; IQR 9.9-20.1) which subsequently decreased. 48 hours after cardiac arrest choline levels in all patients reached subnormal levels at a median of 4.0 µmol/L (IQR 3-4.9; p = 0.001). Subsequently, choline levels normalized within seven days. There was no significant difference in choline levels when groups were analyzed in relation to neurological outcome. Conclusions Our data indicate a choline deficiency in the early postresucitation phase. This could potentially result in impaired cell membrane recovery. The detailed characterization of the early choline time course may aid in planning of choline supplementation trials. In a limited number of patients, choline was not promising as a biomarker for outcome prediction. PMID:24098804

Serial plasma choline measurements after cardiac arrest in patients undergoing mild therapeutic hypothermia: a prospective observational pilot trial.

PubMed

Storm, Christian; Danne, Oliver; Ueland, Per Magne; Leithner, Christoph; Hasper, Dietrich; Schroeder, Tim

2013-01-01

Choline is related to phospholipid metabolism and is a marker for global ischaemia with a small reference range in healthy volunteers. The aim of our study was to characterize the early kinetics of plasma free choline in patients after cardiac arrest. Additionally, we investigated the potential of plasma free choline to predict neurological outcome. Twenty patients admitted to our medical intensive care unit were included in this prospective, observational trial. All patients were enrolled between May 2010 and May 2011. They received post cardiac arrest treatment including mild therapeutic hypothermia which was initiated with a combination of cold fluid and a feedback surface cooling device according to current guidelines. Sixteen blood samples per patient were analysed for plasma free choline levels within the first week after resuscitation. Choline was detected by liquid chromatography-tandem mass spectrometry. Most patients showed elevated choline levels on admission (median 14.8 µmol/L; interquartile range; IQR 9.9-20.1) which subsequently decreased. 48 hours after cardiac arrest choline levels in all patients reached subnormal levels at a median of 4.0 µmol/L (IQR 3-4.9; p = 0.001). Subsequently, choline levels normalized within seven days. There was no significant difference in choline levels when groups were analyzed in relation to neurological outcome. Our data indicate a choline deficiency in the early postresucitation phase. This could potentially result in impaired cell membrane recovery. The detailed characterization of the early choline time course may aid in planning of choline supplementation trials. In a limited number of patients, choline was not promising as a biomarker for outcome prediction.

ErbB2 and EGFR are downmodulated during the differentiation of 3T3-L1 preadipocytes.

PubMed

Pagano, Eleonora; Calvo, Juan Carlos

2003-10-15

The expression of receptors belonging to the epidermal growth factor receptor subfamily has been largely studied these last years in epithelial cells mainly as involved in cell proliferation and malignant progression. Although much work has focused on the role of these growth factor receptors in the differentiation of a variety of tissues, there is little information in regards to normal stromal cells. We investigated erbB2 expression in the murine fibroblast cell line Swiss 3T3L1, which naturally or hormonally induced undergoes adipocyte differentiation. We found that the Swiss 3T3-L1 fibroblasts express erbB2, in addition to EGFR, and in a quantity comparable to or even greater than the breast cancer cell line T47D. Proliferating cells increased erbB2 and EGFR levels when reaching confluence up to 4- and 10-fold, respectively. This expression showed a significant decrease when growth-arrested cells were stimulated to differentiate with dexamethasone and isobutyl-methylxanthine. Differentiated cells presented a decreased expression of both erbB2 and EGFR regardless of whether the cells were hormonally or spontaneously differentiated. EGF stimulation of serum-starved cells increased erbB2 tyrosine phosphorylation and retarded erbB2 migration in SDS-PAGE, suggesting receptor association and activation. Heregulin-alpha1 and -beta1, two EGF related factors, had no effect on erbB2 or EGFR phosphorylation. Although 3T3-L1 cells expressed heregulin, its specific receptors, erbB3 and erbB4, were not found. This is the first time in which erbB2 is reported to be expressed in an adipocytic cell line which does not depend on non EGF family growth factors (thyroid hormone, growth hormone, etc.) to accomplish adipose differentiation. Since erbB2 and EGFR expression were downmodulated as differentiation progressed it is conceivable that a mechanism of switching from a mitogenic to a differentiating signaling pathway may be involved, through regulation of the expression of these growth factor receptors. Copyright 2003 Wiley-Liss, Inc.

Tibial tunnel defect size as a risk factor in growth arrest following paediatric transphyseal anterior cruciate ligament reconstruction: an anatomical study.

PubMed

Pananwala, Hasitha; Jabbar, Yaser; Mills, Leonora; Symes, Michael; Nandapalan, Haren; Sefton, Andrew; Delungahawatte, Lasitha; Dao, Quang

2016-09-01

There is ongoing controversy regarding growth disturbances in younger patients undergoing anterior cruciate ligament reconstructions. Animal models have shown that an injury of 7-9% of the physeal area is a risk factor for growth disturbances. A total of 39 magnetic resonance imaging studies of the knee were examined. The proximal tibial physeal area was determined using a calibrated 'region of interest' ligature encompassing the tibial physis in the axial plane. The potential defect left by commonly used drill sizes was calculated as a percentage of the physeal area. A 7-mm drill leaves a mean defect of 1.45% physeal area (range: 1.11-1.89%, SD: 0.28, 95% CI: ±0.09), 8-mm drill leaves a 1.84% mean defect (range: 1.43-2.49%, SD: 0.38, 95% CI: ±0.12) and a 9-mm drill leaves a 2.30% mean defect (range: 1.83-3.19%, SD: 0.58, 95% CI: ±0.17). At 55°, 7-mm drill leaves a mean defect of 1.96% (range: 1.32-2.28%, SD: 0.37, 95% CI: ±0.12), 8-mm drill leaves a mean defect of 2.19% (range: 1.71-2.95%, SD: 0.46, 95% CI: ±0.14) and a 9-mm drill leaves a mean defect of 2.76% (range: 2.16-3.73%, SD: 0.58, 95% CI: ±0.18). There was a statistically significant difference in the tunnel area with a change of drill angle (7-mm drill P = 0.005, 8-mm drill P = 0.001, 9-mm drill P = 0.001). On the basis of this study in the context of animal model and observational evidence, the area of physeal injury using drill tunnels for anterior cruciate ligament reconstruction would not appear to contribute to potential growth disturbances. © 2016 Royal Australasian College of Surgeons.

Chromosomal instability in mouse embryonic fibroblasts null for the transcriptional co-repressor Ski

PubMed Central

Marcelain, Katherine; Armisen, Ricardo; Aguirre, Adam; Ueki, Nobuhide; Toro, Jessica; Colmenares, Clemencia; Hayman, Michael J

2011-01-01

Ski is a transcriptional regulator that has been considered an oncoprotein, given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski−/− mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chromatin/chromosome bridges as the major cause of micronuclei formation and the subsequent aneuploidy. Although these cells arrested in mitosis after treatment with spindle disrupting drugs and exhibited a delayed metaphase/anaphase transition, Spindle Assembly Checkpoint (SAC) was not sufficient to prevent chromosome missegregation, consistent with a weakened SAC. Our in vivo analysis also showed dynamic metaphase plate rearrangements with switches in polarity in cells arrested in metaphase. Importantly, after ectopic expression of Ski the cells that displayed this metaphase arrest died directly during metaphase or after aberrant cell division, relating SAC activation and mitotic cell death. This increased susceptibility to undergo mitosis-associated cell death reduced the number of micronuclei-containing cells. The presented data support a new role for Ski in the mitotic process and in maintenance of genetic stability, providing insights into the mechanism of tumor suppression mediated by this protein. PMID:21412778

Cerebral oximetry during infant cardiac surgery: evaluation and relationship to early postoperative outcome.

PubMed

Kussman, Barry D; Wypij, David; DiNardo, James A; Newburger, Jane W; Mayer, John E; del Nido, Pedro J; Bacha, Emile A; Pigula, Frank; McGrath, Ellen; Laussen, Peter C

2009-04-01

We examined changes in cerebral oxygen saturation during infant heart surgery and its relationship to anatomic diagnosis and early outcome. Regional cerebral oxygen saturation (rSO(2)) was measured by near-infrared spectroscopy in 104 infants undergoing biventricular repair without aortic arch obstruction as part of a randomized trial of hemodilution to a hematocrit of 25% vs 35%. Before cardiopulmonary bypass (CPB), infants with tetralogy of Fallot had higher rSO(2) values compared to those with D-transposition of the great arteries (D-TGA) or ventricular septal defect (P < 0.001). During CPB cooling, low flow, and at the termination of CPB, D-TGA subjects had the highest rSO(2) values (P < 0.001). There were no significant associations between intraoperative rSO(2) and early postoperative outcomes after adjustment for diagnosis. In 39 D-TGA subjects with > or =5 min of deep hypothermic circulatory arrest (DHCA), there was no correlation between the rSO(2) (91% +/- 6%) or hematocrit (29.2% +/- 5.5%) at the onset of arrest and the rate of decline in rSO(2) during arrest. Intraoperative rSO(2) varies according to anatomic diagnosis but accounts for very little of the variance in early outcome. As measured by frontal near-infrared spectroscopy, higher levels of hematocrit and current perfusion techniques appear to provide an adequate oxygen reservoir prior to relatively short periods of DHCA.

Chromosomal instability in mouse embryonic fibroblasts null for the transcriptional co-repressor Ski.

PubMed

Marcelain, Katherine; Armisen, Ricardo; Aguirre, Adam; Ueki, Nobuhide; Toro, Jessica; Colmenares, Clemencia; Hayman, Michael J

2012-01-01

Ski is a transcriptional regulator that has been considered an oncoprotein given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski-/- mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chromatin/chromosome bridges as the major cause of micronuclei (MN) formation and the subsequent aneuploidy. Although these cells arrested in mitosis after treatment with spindle disrupting drugs and exhibited a delayed metaphase/anaphase transition, spindle assembly checkpoint (SAC) was not sufficient to prevent chromosome missegregation, consistent with a weakened SAC. Our in vivo analysis also showed dynamic metaphase plate rearrangements with switches in polarity in cells arrested in metaphase. Importantly, after ectopic expression of Ski the cells that displayed this metaphase arrest died directly during metaphase or after aberrant cell division, relating SAC activation and mitotic cell death. This increased susceptibility to undergo mitosis-associated cell death reduced the number of MN-containing cells. The presented data support a new role for Ski in the mitotic process and in maintenance of genetic stability, providing insights into the mechanism of tumor suppression mediated by this protein. Copyright © 2011 Wiley Periodicals, Inc.

Patterns of premature physeal arrest: MR imaging of 111 children.

PubMed

Ecklund, Kirsten; Jaramillo, Diego

2002-04-01

The purpose of this study was to use MR imaging, especially fat-suppressed three-dimensional (3D) spoiled gradient-recalled echo sequences, to identify patterns of growth arrest after physeal insult in children. We evaluated 111 children with physeal bone bridges (median age, 11.4 years) using MR imaging to analyze bridge size, location in physis, signal intensity, growth recovery lines, avascular necrosis, and metaphyseal cartilage tongues. Fifty-eight patients underwent fat-suppressed 3D spoiled gradient-recalled echo imaging with physeal mapping. The cause, bone involved, radiographic appearance, and surgical interventions (60/111) were also correlated. Data were analyzed with the two-tailed Fisher's exact test. Posttraumatic bridges, accounting for 70% (78/111) of patients, were most often distal, especially of the tibia (n = 43) and femur (n = 14), whereas those due to the other miscellaneous causes were more frequently proximal (p < 0.0001). The position of the bridge in the physis was related to the bone involved (p < 0.0001). Sixty-five percent of distal tibial bridges involved the anteromedial physis, whereas 60% of the distal femoral arrests were central. Larger bridges had higher T1 signal intensity (p < 0.008). Oblique growth recovery lines were seen exclusively with bridges involving the peripheral physis (p = 0.002) and smaller, more potentially resectable bridges. Metaphyseal cartilaginous tongues were seen with all causes, but avascular necrosis was exclusively posttraumatic (p = 0.03). Signal characteristics and bridge size did not vary with the cause. Premature physeal bony bridging in children is most often posttraumatic and disproportionately involves the distal tibia and femur where bridges tend to develop at the sites of earliest physiologic closure, namely anteromedially and centrally, respectively. MR imaging, especially with the use of fat-suppressed 3D spoiled gradient-recalled echo imaging, exquisitely shows the growth disturbance and associated abnormalities that may follow physeal injury and guides surgical management.

Myeloid leukemia factor 1 regulates p53 by suppressing COP1 via COP9 signalosome subunit 3

PubMed Central

Yoneda-Kato, Noriko; Tomoda, Kiichiro; Umehara, Mari; Arata, Yukinobu; Kato, Jun-ya

2005-01-01

Myeloid leukemia factor 1 (MLF1) was first identified as the leukemic fusion protein NPM-MLF1 generated by the t(3;5)(q25.1;q34) chromosomal translocation. Although MLF1 expresses normally in a variety of tissues including hematopoietic stem cells and the overexpression of MLF1 correlates with malignant transformation in human cancer, little is known about how MLF1 is involved in the regulation of cell growth. Here we show that MLF1 is a negative regulator of cell cycle progression functioning upstream of the tumor suppressor p53. MLF1 induces p53-dependent cell cycle arrest in murine embryonic fibroblasts. This action requires a novel binding partner, subunit 3 of the COP9 signalosome (CSN3). A reduction in the level of CSN3 protein with small interfering RNA abrogated MLF1-induced G1 arrest and impaired the activation of p53 by genotoxic stress. Furthermore, ectopic MLF1 expression and CSN3 knockdown inversely affect the endogenous level of COP1, a ubiquitin ligase for p53. Exogenous expression of COP1 overcomes MLF1-induced growth arrest. These results indicate that MLF1 is a critical regulator of p53 and suggest its involvement in leukemogenesis through a novel CSN3–COP1 pathway. PMID:15861129

A Novel ATM/TP53/p21-Mediated Checkpoint Only Activated by Chronic γ-Irradiation

PubMed Central

Sasatani, Megumi; Iizuka, Daisuke; Masuda, Yuji; Inaba, Toshiya; Suzuki, Keiji; Ootsuyama, Akira; Umata, Toshiyuki; Kamiya, Kenji; Suzuki, Fumio

2014-01-01

Different levels or types of DNA damage activate distinct signaling pathways that elicit various cellular responses, including cell-cycle arrest, DNA repair, senescence, and apoptosis. Whereas a range of DNA-damage responses have been characterized, mechanisms underlying subsequent cell-fate decision remain elusive. Here we exposed cultured cells and mice to different doses and dose rates of γ-irradiation, which revealed cell-type-specific sensitivities to chronic, but not acute, γ-irradiation. Among tested cell types, human fibroblasts were associated with the highest levels of growth inhibition in response to chronic γ-irradiation. In this context, fibroblasts exhibited a reversible G1 cell-cycle arrest or an irreversible senescence-like growth arrest, depending on the irradiation dose rate or the rate of DNA damage. Remarkably, when the same dose of γ-irradiation was delivered chronically or acutely, chronic delivery induced considerably more cellular senescence. A similar effect was observed with primary cells isolated from irradiated mice. We demonstrate a critical role for the ataxia telangiectasia mutated (ATM)/tumor protein p53 (TP53)/p21 pathway in regulating DNA-damage-associated cell fate. Indeed, blocking the ATM/TP53/p21 pathway deregulated DNA damage responses, leading to micronucleus formation in chronically irradiated cells. Together these results provide insights into the mechanisms governing cell-fate determination in response to different rates of DNA damage. PMID:25093836

Inhibition of serine/threonine phosphatase PP2A enhances cancer chemotherapy by blocking DNA damage induced defense mechanisms.

PubMed

Lu, Jie; Kovach, John S; Johnson, Francis; Chiang, Jeffrey; Hodes, Richard; Lonser, Russell; Zhuang, Zhengping

2009-07-14

A variety of mechanisms maintain the integrity of the genome in the face of cell stress. Cancer cell response to chemotherapeutic and radiation-induced DNA damage is mediated by multiple defense mechanisms including polo-like kinase 1 (Plk-1), protein kinase B (Akt-1), and/or p53 pathways leading to either apoptosis or cell cycle arrest. Subsequently, a subpopulation of arrested viable cancer cells may remain and recur despite aggressive and repetitive therapy. Here, we show that modulation (activation of Akt-1 and Plk-1 and repression of p53) of these pathways simultaneously results in paradoxical enhancement of the effectiveness of cytotoxic chemotherapy. We demonstrate that a small molecule inhibitor, LB-1.2, of protein phosphatase 2A (PP2A) activates Plk-1 and Akt-1 and decreases p53 abundance in tumor cells. Combined with temozolomide (TMZ; a DNA-methylating chemotherapeutic drug), LB-1.2 causes complete regression of glioblastoma multiforme (GBM) xenografts without recurrence in 50% of animals (up to 28 weeks) and complete inhibition of growth of neuroblastoma (NB) xenografts. Treatment with either drug alone results in only short-term inhibition/regression with all xenografts resuming rapid growth. Combined with another widely used anticancer drug, Doxorubicin (DOX, a DNA intercalating agent), LB-1.2 also causes marked GBM xenograft regression, whereas DOX alone only slows growth. Inhibition of PP2A by LB-1.2 blocks cell-cycle arrest and increases progression of cell cycle in the presence of TMZ or DOX. Pharmacologic inhibition of PP2A may be a general method for enhancing the effectiveness of cancer treatments that damage DNA or disrupt components of cell replication.

The Antioxidant Transcription Factor Nrf2 Negatively Regulates Autophagy and Growth Arrest Induced by the Anticancer Redox Agent Mitoquinone*

PubMed Central

Rao, V. Ashutosh; Klein, Sarah R.; Bonar, Spencer J.; Zielonka, Jacek; Mizuno, Naoko; Dickey, Jennifer S.; Keller, Paul W.; Joseph, Joy; Kalyanaraman, Balaraman; Shacter, Emily

2010-01-01

Mitoquinone (MitoQ) is a synthetically modified, redox-active ubiquinone compound that accumulates predominantly in mitochondria. We found that MitoQ is 30-fold more cytotoxic to breast cancer cells than to healthy mammary cells. MitoQ treatment led to irreversible inhibition of clonogenic growth of breast cancer cells through a combination of autophagy and apoptotic cell death mechanisms. Relatively limited cytotoxicity was seen with the parent ubiquinone coenzyme Q10. Inhibition of cancer cell growth by MitoQ was associated with G1/S cell cycle arrest and phosphorylation of the checkpoint kinases Chk1 and Chk2. The possible role of oxidative stress in MitoQ activity was investigated by measuring the products of hydroethidine oxidation. Increases in ethidium and dihydroethidium levels, markers of one-electron oxidation of hydroethidine, were observed at cytotoxic concentrations of MitoQ. Keap1, an oxidative stress sensor protein that regulates the antioxidant transcription factor Nrf2, underwent oxidation, degradation, and dissociation from Nrf2 in MitoQ-treated cells. Nrf2 protein levels, nuclear localization, and transcriptional activity also increased following MitoQ treatment. Knockdown of Nrf2 caused a 2-fold increase in autophagy and an increase in G1 cell cycle arrest in response to MitoQ but had no apparent effect on apoptosis. The Nrf2-regulated enzyme NQO1 is partly responsible for controlling the level of autophagy. Keap1 and Nrf2 act as redox sensors for oxidative perturbations that lead to autophagy. MitoQ and similar compounds should be further evaluated for novel anticancer activity. PMID:20805228

ALPHA-FETOPROTEIN (AFP), STEM CELLS, AND CANCER: HOW STUDY OF THE PRODUCTION OF AFP DURING CHEMICAL HEPATOCARCINOGENESIS LED TO REAFFIRMATION OF THE STEM CELL THEORY OF CANCER

PubMed Central

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein (AFP) during development, in response to liver injury, and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas (HCC). When the cellular changes in these processes were compared that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as do normal tissues: stem cells, transit-amplifying cells, and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, anti-angiogenesis and differentiation therapy) are directed against the cancer transit amplifying cells. When these therapies are discontinued, the cancer re-forms from the cancer stem cells. Therapy directed toward interruption of the cell-signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of re-growth of the cancer. PMID:18612221

A novel class of pyranocoumarin anti-androgen receptor signaling compounds.

PubMed

Guo, Junming; Jiang, Cheng; Wang, Zhe; Lee, Hyo-Jeong; Hu, Hongbo; Malewicz, Barbara; Lee, Hyo-Jung; Lee, Jae-Ho; Baek, Nam-In; Jeong, Jin-Hyun; Kim, Dae-Keun; Kang, Kyung-Sun; Kim, Sung-Hoon; Lu, Junxuan

2007-03-01

Androgen and the androgen receptor (AR)-mediated signaling are crucial for prostate cancer development. Novel agents that can inhibit AR signaling in ligand-dependent and ligand-independent manners are desirable for the chemoprevention of prostate carcinogenesis and for the treatment of advanced prostate cancer. We have shown recently that the pyranocoumarin compound decursin from the herb Angelica gigas possesses potent anti-AR activities distinct from the anti-androgen bicalutamide. Here, we compared the anti-AR activities and the cell cycle arrest and apoptotic effects of decursin and two natural analogues in the androgen-dependent LNCaP human prostate cancer cell culture model to identify structure-activity relationships and mechanisms. Decursin and its isomer decursinol angelate decreased prostate-specific antigen expression with IC(50) of approximately 1 mumol/L. Both inhibited the androgen-stimulated AR nuclear translocation and transactivation, decreased AR protein abundance through proteasomal degradation, and induced G(0/1) arrest and morphologic differentiation. They also induced caspase-mediated apoptosis and reactive oxygen species at higher concentrations. Furthermore, they lacked the agonist activity of bicalutamide in the absence of androgen and were more potent than bicalutamide for suppressing androgen-stimulated cell growth. Decursinol, which does not contain a side chain, lacked the reactive oxygen species induction and apoptotic activities and exerted paradoxically an inhibitory and a stimulatory effect on AR signaling and cell growth. In conclusion, decursin and decursinol angelate are members of a novel class of nonsteroidal compounds that exert a long-lasting inhibition of both ligand-dependent and ligand-independent AR signaling. The side chain is critical for sustaining the anti-AR activities and the growth arrest and apoptotic effects.

Galbanic acid decreases androgen receptor abundance and signaling and induces G1 arrest in prostate cancer cells

PubMed Central

Zhang, Yong; Kim, Kwan-Hyun; Zhang, Wei; Guo, Yinglu; Kim, Sung-Hoon; Lü, Junxuan

2011-01-01

Androgen receptor (AR) signaling is crucial for the genesis and progression of prostate cancer (PCa). We compared the growth responses of AR(+) LNCaP and LNCaP C4-2 vs. AR(−) DU145 and PC-3 PCa cell lines to galbanic acid (GBA) isolated from the resin of medicinal herb Ferula assafoetida and assessed their connection to AR signaling and cell cycle regulatory pathways. Our results showed that GBA preferentially suppressed AR(+) PCa cell growth than AR(−) PCa cells. GBA induced a caspase-mediated apoptosis that was attenuated by a general caspase inhibitor. Subapoptotic GBA down-regulated AR protein in LNCaP cells primarily through promoting its proteasomal degradation, and inhibited AR-dependent transcription without affecting AR nuclear translocation. Whereas docking simulations predicted binding of GBA to the AR ligand binding domain with similarities and differences with the AR antagonist drug bicalutamide, LNCaP cell culture assays did not detect agonist activity of GBA. GBA and bicalutamide exerted greater than additive inhibitory effect on cell growth when used together. Subapoptotic GBA induced G1 arrest associated with an inhibition of cyclin/CDK4/6 pathway, especially cyclin D1 without the causal involvement of CDK inhibitory proteins P21Cip1 and P27Kip1. In summary, the novelty of GBA as an anti-AR compound resides in the distinction between GBA and bicalutamide with respect to AR protein turnover and a lack of agonist effect. Our observations of anti-AR and cell cycle arrest actions plus the anti-angiogenesis effect reported elsewhere suggest GBA as a multi-targeting drug candidate for the prevention and therapy of PCa. PMID:21328348

Eupatilin, a dietary flavonoid, induces G2/M cell cycle arrest in human endometrial cancer cells.

PubMed

Cho, Jung-Hoon; Lee, Jong-Gyu; Yang, Yeong-In; Kim, Ji-Hyun; Ahn, Ji-Hye; Baek, Nam-In; Lee, Kyung-Tae; Choi, Jung-Hye

2011-08-01

This study is the first to investigate the antiproliferative effect of eupatilin in human endometrial cancer cells. Eupatilin, a naturally occurring flavonoid isolated from Artemisia princeps, has anti-inflammatory, anti-oxidative, and anti-tumor activities. In the present study, we investigated the potential effect of eupatilin on cell growth and its molecular mechanism of action in human endometrial cancer cells. Eupatilin was more potent than cisplatin in inhibiting cell viability in the human endometrial cancer cell lines Hec1A and KLE. Eupatilin showed relatively low cytotoxicity in normal human endometrial cells HES and HESC cells when compared to cisplatin. Eupatilin induced G2/M phase cell cycle arrest in a time- and dose-dependent manner, as indicated by flow cytometry analysis. In addition, treatment of Hec1A cells with eupatilin resulted in a significant increase in the expression of p21(WAF1/CIP1) and in the phosphorylation of Cdc25C and Cdc2. Knockdown of p21 using specific siRNAs significantly compromised eupatilin-induced cell growth inhibition. Interestingly, levels of mutant p53 in Hec1A cells decreased markedly upon treatment with eupatilin, and p53 siRNA significantly increased p21 expression. Moreover, eupatilin modulated the phosphorylation of protein kinases ERK1/2, Akt, ATM, and Chk2. These results suggest that eupatilin inhibits the growth of human endometrial cancer cells via G2/M phase cell cycle arrest through the up-regulation of p21 by the inhibition of mutant p53 and the activation of the ATM/Chk2/Cdc25C/Cdc2 checkpoint pathway. Copyright © 2011 Elsevier Ltd. All rights reserved.

Germline deletion of FAK-related non-kinase delays post-natal cardiomyocyte mitotic arrest

PubMed Central

O’Neill, Thomas J.; Mack, Christopher P.; Taylor, Joan M.

2012-01-01

The cardiomyocyte phenotypic switch from a proliferative to terminally differentiated state impacts normal heart development and pathologic myocardial remodeling, yet the signaling mechanisms that regulate this vital process are incompletely understood. Studies from our lab and others indicate that focal adhesion kinase (FAK) is a critical regulator of cardiac growth and remodeling and we found that expression of the endogenous FAK inhibitor, FAK-related non kinase (FRNK) coincided with postnatal cardiomyocyte arrest. Mis-expression of FRNK in the embryonic heart led to pre-term lethality associated with reduced cardiomyocyte proliferation and led us to speculate that the postnatal FRNK surge might be required to promote quiescence in this growth promoting environment. Herein, we provide strong evidence that endogenous FRNK contributes to post-mitotic arrest. Depletion of FRNK promoted DNA synthesis in post-natal day (P) 10 hearts accompanied by a transient increase in DNA content and multi-nucleation by P14, indicative of DNA replication without cell division. Interestingly, a reduction in tri- and tetra-nucleated cardiomyocytes, concomitant with an increase in bi-nucleated cells by P21, indicated the possibility that FRNK-depleted cardiomyocytes underwent eventual cytokinesis. In support of this conclusion, Aurora B-labeled central spindles (a hallmark of cytokinesis) were observed in tetra-nucleated P20 FRNK−/− but not wt cardiomyocytes, while no evidence of apoptosis was observed. Moreover, hearts from FRNK null mice developed ventricular enlargement that persisted until young adulthood which resulted from myocyte expansion rather than myocyte hypertrophy or interstitial growth. These data indicate that endogenous FRNK serves an important role in limiting DNA synthesis and regulating the un-coupling between DNA synthesis and cytokinesis in the post-natal myocardium. PMID:22555221

A temperature-sensitive dcw1 mutant of Saccharomyces cerevisiae is cell cycle arrested with small buds which have aberrant cell walls.

PubMed

Kitagaki, Hiroshi; Ito, Kiyoshi; Shimoi, Hitoshi

2004-10-01

Dcw1p and Dfg5p in Saccharomyces cerevisiae are homologous proteins that were previously shown to be involved in cell wall biogenesis and to be essential for growth. Dcw1p was found to be a glycosylphosphatidylinositol-anchored membrane protein. To investigate the roles of these proteins in cell wall biogenesis and cell growth, we constructed mutant alleles of DCW1 by random mutagenesis, introduced them into a Deltadcw1 Deltadfg5 background, and isolated a temperature-sensitive mutant, DC61 (dcw1-3 Deltadfg5). When DC61 cells were incubated at 37 degrees C, most cells had small buds, with areas less than 20% of those of the mother cells. This result indicates that DC61 cells arrest growth with small buds at 37 degrees C. At 37 degrees C, fewer DC61 cells had 1N DNA content and most of them still had a single nucleus located apart from the bud neck. In addition, in DC61 cells incubated at 37 degrees C, bipolar spindles were not formed. These results indicate that DC61 cells, when incubated at 37 degrees C, are cell cycle arrested after DNA replication and prior to the separation of spindle pole bodies. The small buds of DC61 accumulated chitin in the bud cortex, and some of them were lysed, which indicates that they had aberrant cell walls. A temperature-sensitive dfg5 mutant, DF66 (Deltadcw1 dfg5-29), showed similar phenotypes. DCW1 and DFG5 mRNA levels peaked in the G1 and S phases, respectively. These results indicate that Dcw1p and Dfg5p are involved in bud formation through their involvement in biogenesis of the bud cell wall.

Characterisation of cell cycle arrest and terminal differentiation in a maximally proliferative human epithelial tissue: Lessons from the human hair follicle matrix.

PubMed

Purba, Talveen S; Brunken, Lars; Peake, Michael; Shahmalak, Asim; Chaves, Asuncion; Poblet, Enrique; Ceballos, Laura; Gandarillas, Alberto; Paus, Ralf

2017-09-01

Human hair follicle (HF) growth and hair shaft formation require terminal differentiation-associated cell cycle arrest of highly proliferative matrix keratinocytes. However, the regulation of this complex event remains unknown. CIP/KIP family member proteins (p21 CIP1 , p27 KIP1 and p57 KIP2 ) regulate cell cycle progression/arrest, endoreplication, differentiation and apoptosis. Since they have not yet been adequately characterized in the human HF, we asked whether and where CIP/KIP proteins localise in the human hair matrix and pre-cortex in relation to cell cycle activity and HF-specific epithelial cell differentiation that is marked by keratin 85 (K85) protein expression. K85 expression coincided with loss or reduction in cell cycle activity markers, including in situ DNA synthesis (EdU incorporation), Ki-67, phospho-histone H3 and cyclins A and B1, affirming a post-mitotic state of pre-cortical HF keratinocytes. Expression of CIP/KIP proteins was found abundantly within the proliferative hair matrix, concomitant with a role in cell cycle checkpoint control. p21 CIP1 , p27 KIP1 and cyclin E persisted within post-mitotic keratinocytes of the pre-cortex, whereas p57 KIP2 protein decreased but became nuclear. These data imply a supportive role for CIP/KIP proteins in maintaining proliferative arrest, differentiation and anti-apoptotic pathways, promoting continuous hair bulb growth and hair shaft formation in anagen VI. Moreover, post-mitotic hair matrix regions contained cells with enlarged nuclei, and DNA in situ hybridisation showed cells that were >2N in the pre-cortex. This suggests that CIP/KIP proteins might counterbalance cyclin E to control further rounds of DNA replication in a cell population that has a propensity to become tetraploid. These data shed new light on the in situ-biography of human hair matrix keratinocytes on their path of active cell cycling, arrest and terminal differentiation, and showcase the human HF as an excellent, clinically relevant model system for cell cycle physiology research of human epithelial cells within their natural tissue habitat. Crown Copyright © 2017. Published by Elsevier GmbH. All rights reserved.

UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation

PubMed Central

Biever, Jessica J.; Brinkman, Doug; Gardner, Gary

2014-01-01

Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280–320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction. PMID:24591052

Transforming Growth Factor-B Receptors in Human Breast Cancer.

DTIC Science & Technology

1998-05-01

I., Polyak, K., Iavarone, A., and Massagud, J. Kip/ Cip and Ink4 cdk inhibitors cooperate to induce cell cycle arrest in response to TGF-ß. Genes Dev...specimens. Thirdly, we have developped transient transfection assays to determine how specific TßR mutations affect affect receptor function. Using...Growth Factor-ß (TGFß) is the most potent known inhibitor of cell cycle progression of normal mammary epithelial cells; in addition, it causes cells

Axl as a mediator of cellular growth and survival

PubMed Central

Axelrod, Haley; Pienta, Kenneth J.

2014-01-01

The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context. PMID:25344858

Berberine Induces Cell Cycle Arrest in Cholangiocarcinoma Cell Lines via Inhibition of NF-κB and STAT3 Pathways.

PubMed

Puthdee, Nattapong; Seubwai, Wunchana; Vaeteewoottacharn, Kulthida; Boonmars, Thidarut; Cha'on, Ubon; Phoomak, Chatchai; Wongkham, Sopit

2017-01-01

Berberine is a natural compound found in several herbs. Anticancer activity of berberine was reported in several cancers, however, little is known regarding the effects of berberine against cholangiocarcinoma (CCA). In this study, the growth inhibitory effects of berberine on CCA cell lines and its molecular mechanisms were explored. Cell growth and cell cycle distribution were examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. The expression levels of cell cycle regulatory proteins were determined by Western blot analysis. Berberine significantly inhibited growth of CCA cell lines in a dose and time dependent fashion. The inhibition was largely attributed to cell cycle arrest at the G1 phase through the reduction of cyclin D1, and cyclin E. Moreover, berberine could reduce the expression and activation of signal transducers and activator of transcription 3 (STAT3) and probably nuclear factor-kappaB (NF-κB) via suppression of extracellular signal-regulated kinase (ERK) 1/2 action. These results highlight the potential of berberine to be a multi-target agent for CCA treatment.

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

PubMed

Weinert, T A; Hartwell, L H

1990-12-01

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

FGF inhibits the activity of the cyclin B1/CDK1 kinase to induce a transient G₂arrest in RCS chondrocytes.

PubMed

Tran, Tri; Kolupaeva, Victoria; Basilico, Claudio

2010-11-01

Fibroblast growth factors (FGFs) negatively regulate long bone development by inhibiting the proliferation of chondrocytes that accumulate in the G₁ phase of the cycle following FGF treatment. Here we report that FGF also causes a striking but transient delay in mitotic entry in RCS chondrocytes by inactivating the cyclin B1-associated CDK1(CDC2) kinase. As a consequence of this inactivation, cells accumulate in the G₂ phase of the cycle for the first 4-6 hours of the treatment. Cyclin B1/CDK1 activity is then restored and cells reach a G₁ arrest. The reduced cyclin B1/CDK1 activity was accompanied by increased CDK1 inhibitory phosphorylation, likely caused by increased activity and expression of the Myt1 kinase. FGF1 also caused dephosphorylation of the CDC25C phosphatase, that however appears due the inactivation of cyclin B1/CDK1 complex in the CDK1 feedback loop, and not the activation of specific phosphatases. the inactivation of the cyclin B1/CDK1 complex is a direct effect of FGF signaling, and not a consequence of the G₂ arrest as it can be observed also in cells blocked at mitosis by Nocodazole. The Chk1 and AtM/ATR kinase are known to play essential roles in the G₂ checkpoint induced by DNA damage/genotoxic stress, but inhibition of Chk1 or ATM/ATR not only did not prevent, but rather potentiated the FGF-induced G₂ arrest. Additionally our results indicate that the transient G₂ arrest is induced by FGF in RCS cell through mechanisms that are independent of the G₁ arrest, and that the G₂ block is not strictly required for the sustained G₁ arrest but may provide a pausing mechanism that allows the FGF response to be fully established.

Temperature monitoring during cardiopulmonary bypass--do we undercool or overheat the brain?

PubMed

Kaukuntla, Hemanth; Harrington, Deborah; Bilkoo, Inderaj; Clutton-Brock, Tom; Jones, Timothy; Bonser, Robert S

2004-09-01

Brain cooling is an essential component of aortic surgery requiring circulatory arrest and inadequate cooling may lead to brain injury. Similarly, brain hyperthermia during the rewarming phase of cardiopulmonary bypass may also lead to neurological injury. Conventional temperature monitoring sites may not reflect the core brain temperature (Tdegrees). We compared jugular bulb venous temperatures (JB) during deep hypothermic circulatory arrest and normothermic bypass with Nasopharyngeal (NP), Arterial inflow (AI), Oesophageal (O), Venous return (VR), Bladder (B) and Orbital skin (OS) temperatures. 18 patients undergoing deep hypothermia (DH) and 8 patients undergoing normothermic bypass (mean bladder Tdegrees-36.29 degreesC) were studied. For DH, cooling was continued to 15 degreesC NP (mean cooling time-66 min). At pre-determined arterial inflow Tdegrees, NP, JB and O Tdegree's were measured. A 6-channel recorder continuously recorded all Tdegree's using calibrated thermocouples. During the cooling phase of DH, NP lagged behind AI and JB Tdegree's. All these equilibrated at 15 degreesC. During rewarming, JB and NP lagged behind AI and JB was higher than NP at any time point. During normothermic bypass, although NP was reflective of the AI and JB Tdegrees trends, it underestimated peak JB Tdegrees (P=0.001). Towards the end of bypass, peak JB was greater than the arterial inflow Tdegrees (P=0.023). If brain venous outflow Tdegrees (JB) accurately reflects brain Tdegrees, NP Tdegrees is a safe surrogate indicator of cooling. During rewarming, all peripheral sites underestimate brain temperature and caution is required to avoid hyperthermic arterial inflow, which may inadvertently, result in brain hyperthermia.

Ejecta from Targets Strong and Weak: Experimental Measurements of Strength Controlled and Strengthless Craters

NASA Astrophysics Data System (ADS)

Hermalyn, B.

2014-09-01

This study presents novel time-resolved 3D measurements of the impact ejecta through crater formation and the arresting process that ceases growth into a variety of targets exhibiting a spectrum of different strengths of interest on planetary bodies.

Long noncoding RNA growth arrest-specific 5 promotes proliferation and survival of female germline stem cells in vitro.

PubMed

Wang, Jie; Gong, Xiaowen; Tian, Geng G; Hou, Changliang; Zhu, Xiaoqin; Pei, Xiuying; Wang, Yanrong; Wu, Ji

2018-05-05

Female germline stem cells (FGSCs) are proposed to be a key factor for ameliorating female infertility. Previously we have shown that neonatal and adult FGSCs could be isolated and purified from mouse ovarian tissues. The long noncoding (lnc) RNA growth arrest-specific 5 sequence (GAS5) transcribed from mammalian genomes plays important regulatory roles in various developmental processes. However, there is no study on the relationship between GAS5 and FGSC development in vitro. In this study, we showed that GAS5 was highly expressed in the neonatal mouse ovary and was located in both FGSCs and oocytes. GAS5 facilitated FGSC proliferation and promoted their survival in vitro. Moreover, GAS5 also inhibited apoptosis of cultured FGSCs. These findings indicate that GAS5 is a crucial regulator of FGSC development. This might serve as a foundation for a strategy of lncRNA-directed diagnosis or treatment of female infertility. Copyright © 2018. Published by Elsevier B.V.

Osteochondral repair in hemophilic ankle arthropathy: from current options to future perspectives

PubMed Central

BUDA, ROBERTO; CAVALLO, MARCO; CASTAGNINI, FRANCESCO; FERRANTI, ENRICO; NATALI, SIMONE; GIANNINI, SANDRO

2015-01-01

Young hemophilic patients are frequently affected by ankle arthropathy. At the end stage of the disease, the current treatments are arthrodesis and arthroplasty, which have significant drawbacks. Validated procedures capable of slowing down or even arresting the progression towards the end stage are currently lacking. This review aims to discuss the rationale for and feasibility of applying, in mild hemophilic ankle arthropathy, the main techniques currently used to treat osteochondral defects, focusing in particular on ankle distraction, chondrocyte implantation, mesenchymal stem cell transplantation, allograft transplantation and the use of growth factors. To date, ankle distraction is the only procedure that has been successfully used in hemophilic ankle arthropathy. The use of mesenchymal stem cells have recently been evaluated as feasible for osteochondral repair in hemophilic patients. There may be a rationale for the use of growth factors if they are combined with the previous techniques, which could be useful to arrest the progression of the degeneration or delay end-stage procedures. PMID:26904526

The antiviral agent cidofovir [(S)-1-(3-hydroxy-2-phosphonyl-methoxypropyl)cytosine] has pronounced activity against nasopharyngeal carcinoma grown in nude mice.

PubMed

Neyts, J; Sadler, R; De Clercq, E; Raab-Traub, N; Pagano, J S

1998-02-01

The effect of the antiviral agent (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl) cytosine (cidofovir) on the EBV-associated tumor nasopharyngeal carcinoma (NPC) was evaluated in NPC xenografts in athymic mice. Intratumoral injection arrested tumor growth within 1 week, and by 4 weeks, tumors regressed to 8-75% (39 +/- 33%) of the original size, whereas control tumors injected with PBS grew to 282 +/- 25% of the original size. Ganciclovir slowed but did not arrest or cause regression of tumor growth. A striking antitumor effect was also produced by systemic administration; at 4 weeks, tumors were 79 +/- 49% of the original size, compared with 635 +/- 91% for the controls. Widespread apoptosis was detected after treatment for 2-6 days in C15 as well as two other NPC xenografts, C17 and C18; the latter NPCs have mutations in the p53 gene. These data indicate that cidofovir induces rapid cell death through apoptosis in EBV-transformed epithelial cells.

Effects of cholera toxin and isobutylmethylxanthine on growth of human fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Espinoza, B.; Wharton, W.

1986-08-01

Cholera toxin produced a dose-dependent decrease in the restimulation of G0/G1 traverse in density-arrested human fibroblasts but did not inhibit the stimulation of cells arrested in G0 after serum starvation at low density. In addition, cholera toxin did not inhibit the proliferation of sparse logarithmically growing human fibroblasts, even when low concentrations of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) were also present. However, the final density to which sparse cells grew was limited by cholera toxin, when added either alone or together with low concentrations of IBMX. In contrast, high concentrations of the phosphodiesterase inhibitor alone produced a profound inhibition inmore » the growth of sparse human fibrobasts. IBMX produced an inhibition both in the G1 and in the G2 phases of the cell cycle by a mechanism(s) that was not related to the magnitude of the increases in adenosine 3,5-cyclic monophosphate concentrations.« less

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.

Human breast tissue disposition and bioactivity of limonene in women with early-stage breast cancer.

PubMed

Miller, Jessica A; Lang, Julie E; Ley, Michele; Nagle, Ray; Hsu, Chiu-Hsieh; Thompson, Patricia A; Cordova, Catherine; Waer, Amy; Chow, H-H Sherry

2013-06-01

Limonene is a bioactive food component found in citrus peel oil that has shown chemopreventive and chemotherapeutic activities in preclinical studies. We conducted an open-label pilot clinical study to determine the human breast tissue disposition of limonene and its associated bioactivity. We recruited 43 women with newly diagnosed operable breast cancer electing to undergo surgical excision to take 2 grams of limonene daily for two to six weeks before surgery. Blood and breast tissue were collected to determine drug/metabolite concentrations and limonene-induced changes in systemic and tissue biomarkers of breast cancer risk or carcinogenesis. Limonene was found to preferentially concentrate in the breast tissue, reaching high tissue concentration (mean = 41.3 μg/g tissue), whereas the major active circulating metabolite, perillic acid, did not concentrate in the breast tissue. Limonene intervention resulted in a 22% reduction in cyclin D1 expression (P = 0.002) in tumor tissue but minimal changes in tissue Ki67 and cleaved caspase-3 expression. No significant changes in serum leptin, adiponectin, TGF-β1, insulin-like growth factor binding protein-3 (IGFBP-3), and interleukin-6 (IL-6) levels were observed following limonene intervention. There was a small but statistically significant postintervention increase in insulin-like growth factor I (IGF-I) levels. We conclude that limonene distributed extensively to human breast tissue and reduced breast tumor cyclin D1 expression that may lead to cell-cycle arrest and reduced cell proliferation. Furthermore, placebo-controlled clinical trials and translational research are warranted to establish limonene's role for breast cancer prevention or treatment.

Invited review: Pre- and postnatal adipose tissue development in farm animals: from stem cells to adipocyte physiology.

PubMed

Louveau, I; Perruchot, M-H; Bonnet, M; Gondret, F

2016-11-01

Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to other tissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functional maturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health.

Mapping human long bone compartmentalisation during ontogeny: a new methodological approach.

PubMed

Cambra-Moo, Oscar; Nacarino Meneses, Carmen; Rodríguez Barbero, Miguel Ángel; García Gil, Orosia; Rascón Pérez, Josefina; Rello-Varona, Santiago; Campo Martín, Manuel; González Martín, Armando

2012-06-01

Throughout ontogeny, human bones undergo differentiation in terms of shape, size and tissue type; this is a complex scenario in which the variations in the tissue compartmentalisation of the cortical bone are still poorly understood. Currently, compartmentalisation is studied using methodologies that oversimplify the bone tissue complexity. Here, we present a new methodological approach that integrates a histological description and a mineral content analysis to study the compartmentalisation of the whole mineralised and non-mineralised tissues (i.e., spatial distribution in long bone sections). This new methodology, based on Geographical Information System (GIS) software, allows us to draw areas of interest (i.e., tracing vectorial shapes which are quantifiable) in raw images that are extracted from microscope and compared them spatially in a semi-automatic and quantitative fashion. As an example of our methodology, we have studied the tibiae from individuals with different age at death (infant, juvenile and adult). The tibia's cortical bone presents a well-formed fibrolamellar bone, in which remodelling is clearly evidenced from early ontogeny, and we discuss the existence of "lines of arrested growth". Concurrent with the histological variation, Raman and FT-IR spectroscopy analyses corroborate that the mineral content in the cortical bone changes differentially. The anterior portion of the tibia remains highly pierced and is less crystalline than the rest of the cortex during growth, which is evidence of more active and continuous remodelling. Finally, while porosity and other "non-mineralised cavities" are largely modified, the mineralised portion and the marrow cavity size persist proportionally during ontogeny. Copyright © 2012 Elsevier Inc. All rights reserved.

Tbx1 regulates oral epithelial adhesion and palatal development

PubMed Central

Funato, Noriko; Nakamura, Masataka; Richardson, James A.; Srivastava, Deepak; Yanagisawa, Hiromi

2012-01-01

Cleft palate, the most frequent congenital craniofacial birth defect, is a multifactorial condition induced by the interaction of genetic and environmental factors. In addition to complete cleft palate, a large number of human cases involve soft palate cleft and submucosal cleft palate. However, the etiology of these forms of cleft palate has not been well understood. T-box transcriptional factor (Tbx) family of transcriptional factors has distinct roles in a wide range of embryonic differentiation or response pathways. Here, we show that genetic disruption of Tbx1, a major candidate gene for the human congenital disorder 22q11.2 deletion syndrome (Velo-cardio-facial/DiGeorge syndrome), led to abnormal epithelial adhesion between the palate and mandible in mouse, resulting in various forms of cleft palate similar to human conditions. We found that hyperproliferative epithelium failed to undergo complete differentiation in Tbx1-null mice (Tbx1−/−). Inactivation of Tbx1 specifically in the keratinocyte lineage (Tbx1KCKO) resulted in an incomplete cleft palate confined to the anterior region of the palate. Interestingly, Tbx1 overexpression resulted in decreased cell growth and promoted cell-cycle arrest in MCF7 epithelial cells. These findings suggest that Tbx1 regulates the balance between proliferation and differentiation of keratinocytes and is essential for palatal fusion and oral mucosal differentiation. The impaired adhesion separation of the oral epithelium together with compromised palatal mesenchymal growth is an underlying cause for various forms of cleft palate phenotypes in Tbx1−/− mice. Our present study reveals new pathogenesis of incomplete and submucous cleft palate during mammalian palatogenesis. PMID:22371266

Scorpion (Androctonus crassicauda) venom limits growth of transformed cells (SH-SY5Y and MCF-7) by cytotoxicity and cell cycle arrest.

PubMed

Zargan, Jamil; Sajad, Mir; Umar, Sadiq; Naime, Mohammad; Ali, Shakir; Khan, Haider A

2011-08-01

The purpose of study was to examine the cytotoxic and anti-cancer properties along with addressing the plausible pathway followed by scorpion venom to reduce cell viability in SH-SY5Y and MCF-7 cells. Following exposure of cells with scorpion venom, cytotoxicity was estimated using MTT and lactate dehydrogenase assays. Apoptotic effects were measured by assessment of mitochondrial membrane potential, reactive nitrogen species, DNA fragmentation, and caspase-3 activity whereas antiproliferative effect was assayed using BrdU incorporation. Our results indicate that scorpion venom causes suppression of proliferation by arresting S-phase and induction of apoptosis through increased nitric oxide production, caspase-3 activity and depolarization of mitochondrial membrane. Induction of apoptosis and arrest of DNA synthesis are critical determinant factors for development of anti cancer drugs. These properties may lead to isolation of effective molecule(s) with potential anticancer activity from scorpion venom of Androctonus crassicauda. Copyright © 2011 Elsevier Inc. All rights reserved.

Pyruvate kinase isoform expression alters nucleotide synthesis to impact cell proliferation

PubMed Central

Lunt, Sophia Y.; Muralidhar, Vinayak; Hosios, Aaron M.; Israelsen, William J.; Gui, Dan Y.; Newhouse, Lauren; Ogrodzinski, Martin; Hecht, Vivian; Xu, Kali; Acevedo, Paula N. Marín; Hollern, Daniel P.; Bellinger, Gary; Dayton, Talya L.; Christen, Stefan; Elia, Ilaria; Dinh, Anh T.; Stephanopoulos, Gregory; Manalis, Scott R.; Yaffe, Michael B.; Andrechek, Eran R.; Fendt, Sarah-Maria; Heiden, Matthew G. Vander

2014-01-01

SUMMARY Metabolic regulation influences cell proliferation. The influence of pyruvate kinase isoforms on tumor cells has been extensively studied, but whether PKM2 is required for normal cell proliferation is unknown. We examine how PKM2-deletion affects proliferation and metabolism in non-transformed, non-immortalized PKM2-expressing primary cells. We find that deletion of PKM2 in primary cells results in PKM1 expression and proliferation arrest. PKM1 expression, rather than PKM2 loss, is responsible for this effect, and proliferation arrest cannot be explained by cell differentiation, senescence, death, changes in gene expression, or prevention of cell growth. Instead, PKM1 expression impairs nucleotide production and the ability to synthesize DNA and progress through the cell cycle. Nucleotide biosynthesis is limiting, as proliferation arrest is characterized by severe thymidine depletion, and supplying exogenous thymine rescues both nucleotide levels and cell proliferation. Thus, PKM1 expression promotes a metabolic state that is unable to support DNA synthesis. PMID:25482511

Autoimmune control of lesion growth in CNS with minimal damage

NASA Astrophysics Data System (ADS)

Mathankumar, R.; Mohan, T. R. Krishna

2013-07-01

Lesions in central nervous system (CNS) and their growth leads to debilitating diseases like Multiple Sclerosis (MS), Alzheimer's etc. We developed a model earlier [1, 2] which shows how the lesion growth can be arrested through a beneficial auto-immune mechanism. We compared some of the dynamical patterns in the model with different facets of MS. The success of the approach depends on a set of control parameters and their phase space was shown to have a smooth manifold separating the uncontrolled lesion growth region from the controlled. Here we show that an optimal set of parameter values exist in the model which minimizes system damage while, at once, achieving control of lesion growth.

Effect of beta-carotene-rich tomato lycopene beta-cyclase ( tlcy-b) on cell growth inhibition in HT-29 colon adenocarcinoma cells.

PubMed

Palozza, Paola; Bellovino, Diana; Simone, Rossella; Boninsegna, Alma; Cellini, Francesco; Monastra, Giovanni; Gaetani, Sancia

2009-07-01

Lycopene beta-cyclase (tlcy-b) tomatoes, obtained by modulating carotenogenesis via genetic engineering, contain a large amount of beta-carotene, as clearly visible by their intense orange colour. In the present study we have subjected tlcy-b tomatoes to an in vitro simulated digestion and analysed the effects of digestate on cell proliferation. To this aim we used HT-29 human colon adenocarcinoma cells, grown in monolayers, as a model. Digested tomatoes were diluted (20 ml, 50 ml and 100 ml/l) in culture medium and added to the cells for different incubation times (24 h, 48 h and 72 h). Inhibition of cell growth by tomato digestate was dose-dependent and resulted from an arrest of cell cycle progression at the G0/G1 and G2/M phase and by apoptosis induction. A down-regulation of cyclin D1, Bcl-2 and Bcl-xl expression was observed. We also found that heat treatment of samples before digestion enhanced beta-carotene release and therefore cell growth inhibition. To induce with purified beta-carotene solubilised in tetrahydrofuran the same cell growth inhibition obtained with the tomato digestate, a higher amount of the carotenoid was necessary, suggesting that beta-carotene micellarised during digestion is utilised more efficiently by the cells, but also that other tomato molecules, reasonably made available during digestion, may be present and cooperate with beta-carotene in promoting cell growth arrest.

Direct targeting of MEK1/2 and RSK2 by silybin induces cell cycle arrest and inhibits melanoma cell growth

PubMed Central

Lee, Mee-Hyun; Huang, Zunnan; Kim, Dong Joon; Kim, Sung-Hyun; Kim, Myoung Ok; Lee, Sung-Young; Xie, Hua; Park, Si Jun; Kim, Jae Young; Kundu, Joydeb Kumar; Bode, Ann M.; Surh, Young-Joon; Dong, Zigang

2013-01-01

Abnormal functioning of multiple gene products underlies the neoplastic transformation of cells. Thus, chemopreventive and/or chemotherapeutic agents with multigene targets hold promise in the development of effective anticancer drugs. Silybin, a component of milk thistle, is a natural anticancer agent. In the present study, we investigated the effect of silybin on melanoma cell growth and elucidated its molecular targets. Our study revealed that silybin attenuated the growth of melanoma xenograft tumors in nude mice. Silybin inhibited the kinase activity of mitogen-activated protein kinase kinase (MEK)-1/2 and ribosomal S6 kinase (RSK)-2 in melanoma cells. The direct binding of silybin with MEK1/2 and RSK2 was explored using a computational docking model. Treatment of melanoma cells with silybin attenuated the phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 and RSK2, which are regulated by the upstream kinases MEK1/2. The blockade of MEK1/2-ERK1/2-RSK2 signaling by silybin resulted in a reduced activation of nuclear factor-kappaB, activator protein-1 and signal transducer and activator of transcription-3, which are transcriptional regulators of a variety of proliferative genes in melanomas. Silybin, by blocking the activation of these transcription factors, induced cell cycle arrest at the G1 phase and inhibited melanoma cell growth in vitro and in vivo. Taken together, silybin suppresses melanoma growth by directly targeting MEK- and RSK-mediated signaling pathways. PMID:23447564

The evolution of complex life cycles when parasite mortality is size- or time-dependent.

PubMed

Ball, M A; Parker, G A; Chubb, J C

2008-07-07

In complex cycles, helminth larvae in their intermediate hosts typically grow to a fixed size. We define this cessation of growth before transmission to the next host as growth arrest at larval maturity (GALM). Where the larval parasite controls its own growth in the intermediate host, in order that growth eventually arrests, some form of size- or time-dependent increase in its death rate must apply. In contrast, the switch from growth to sexual reproduction in the definitive host can be regulated by constant (time-independent) mortality as in standard life history theory. We here develop a step-wise model for the evolution of complex helminth life cycles through trophic transmission, based on the approach of Parker et al. [2003a. Evolution of complex life cycles in helminth parasites. Nature London 425, 480-484], but which includes size- or time-dependent increase in mortality rate. We assume that the growing larval parasite has two components to its death rate: (i) a constant, size- or time-independent component, and (ii) a component that increases with size or time in the intermediate host. When growth stops at larval maturity, there is a discontinuous change in mortality to a constant (time-independent) rate. This model generates the same optimal size for the parasite larva at GALM in the intermediate host whether the evolutionary approach to the complex life cycle is by adding a new host above the original definitive host (upward incorporation), or below the original definitive host (downward incorporation). We discuss some unexplored problems for cases where complex life cycles evolve through trophic transmission.

Relationship between plant growth and cytological effect in root apical meristem after exposure of wheat dry seeds to carbon ion beams

NASA Astrophysics Data System (ADS)

Liu, Qingfang; Wang, Zhuanzi; Zhou, Libin; Qu, Ying; Lu, Dong; Yu, Lixia; Du, Yan; Jin, Wenjie; Li, Wenjian

2013-06-01

In order to analyze the relationship between plant growth and cytological effects, wheat dry seeds were exposed to various doses of 12C6+ beams and the biological endpoints reflecting plant growth and root apical meristem (RAM) activities were investigated. The results showed that most of the seeds were able to germinate normally within all dose range, while the plant survival rate descended at higher doses. The seedling growth including root length and seedling height also decreased significantly at higher doses. Mitotic index (MI) in RAM had no changes at 10 and 20 Gy and decreased obviously at higher doses and the proportion of prophase cells had the same trend with MI. These data suggested that RAM cells experienced cell cycle arrest, which should be responsible for the inhibition of root growth after exposure to higher doses irradiation. Moreover, various types of chromosome aberrations (CAs) were observed in the mitotic cells. The frequencies of mitotic cells with lagging chromosomes and these with anaphase bridges peaked around 60 Gy, while the frequencies of these with fragments increased as the irradiation doses increased up to 200 Gy. The total frequencies of mitotic cells with CAs induced by irradiation increased significantly with the increasing doses. The serious damage of mitotic chromosomes maybe caused cell cycle arrest or cell death. These findings suggested that the influences of 12C6+ beams irradiation on plant growth were related to the alternation of mitotic activities and the chromosomal damages in RAM.

Saccharomyces cerevisiae biofilm tolerance towards systemic antifungals depends on growth phase.

PubMed

Bojsen, Rasmus; Regenberg, Birgitte; Folkesson, Anders

2014-12-04

Biofilm-forming Candida species cause infections that can be difficult to eradicate, possibly because of antifungal drug tolerance mechanisms specific to biofilms. In spite of decades of research, the connection between biofilm and drug tolerance is not fully understood. We used Saccharomyces cerevisiae as a model for drug susceptibility of yeast biofilms. Confocal laser scanning microscopy showed that S. cerevisiae and C. glabrata form similarly structured biofilms and that the viable cell numbers were significantly reduced by treatment of mature biofilms with amphotericin B but not voriconazole, flucytosine, or caspofungin. We showed that metabolic activity in yeast biofilm cells decreased with time, as visualized by FUN-1 staining, and mature, 48-hour biofilms contained cells with slow metabolism and limited growth. Time-kill studies showed that in exponentially growing planktonic cells, voriconazole had limited antifungal activity, flucytosine was fungistatic, caspofungin and amphotericin B were fungicidal. In growth-arrested cells, only amphotericin B had antifungal activity. Confocal microscopy and colony count viability assays revealed that the response of growing biofilms to antifungal drugs was similar to the response of exponentially growing planktonic cells. The response in mature biofilm was similar to that of non-growing planktonic cells. These results confirmed the importance of growth phase on drug efficacy. We showed that in vitro susceptibility to antifungal drugs was independent of biofilm or planktonic growth mode. Instead, drug tolerance was a consequence of growth arrest achievable by both planktonic and biofilm populations. Our results suggest that efficient strategies for treatment of yeast biofilm might be developed by targeting of non-dividing cells.

Partial pneumonectomy of telomerase null mice carrying shortened telomeres initiates cell growth arrest resulting in a limited compensatory growth response

PubMed Central

Jackson, Sha-Ron; Lee, Jooeun; Reddy, Raghava; Williams, Genevieve N.; Kikuchi, Alexander; Freiberg, Yael; Warburton, David

2011-01-01

Telomerase mutations and significantly shortened chromosomal telomeres have recently been implicated in human lung pathologies. Natural telomere shortening is an inevitable consequence of aging, which is also a risk factor for development of lung disease. However, the impact of shortened telomeres and telomerase dysfunction on the ability of lung cells to respond to significant challenge is still largely unknown. We have previously shown that lungs of late generation, telomerase null B6.Cg-Terctm1Rdp mice feature alveolar simplification and chronic stress signaling at baseline, a phenocopy of aged lung. To determine the role telomerase plays when the lung is challenged, B6.Cg-Terctm1Rdp mice carrying shortened telomeres and wild-type controls were subjected to partial pneumonectomy. We found that telomerase activity was strongly induced in alveolar epithelial type 2 cells (AEC2) of the remaining lung immediately following surgery. Eighty-six percent of wild-type animals survived the procedure and exhibited a burst of early compensatory growth marked by upregulation of proliferation, stress response, and DNA repair pathways in AEC2. In B6.Cg-Terctm1Rdp mice carrying shortened telomeres, response to pneumonectomy was characterized by decreased survival, diminished compensatory lung growth, attenuated distal lung progenitor cell response, persistent DNA damage, and cell growth arrest. Overall, survival correlated strongly with telomere length. We conclude that functional telomerase and properly maintained telomeres play key roles in both long-term survival and the early phase of compensatory lung growth following partial pneumonectomy. PMID:21460122

Critical role of the axonal guidance cue EphrinB2 in lung growth, angiogenesis, and repair.

PubMed

Vadivel, Arul; van Haaften, Tim; Alphonse, Rajesh S; Rey-Parra, Gloria-Juliana; Ionescu, Lavinia; Haromy, Al; Eaton, Farah; Michelakis, Evangelos; Thébaud, Bernard

2012-03-01

Lung diseases characterized by alveolar damage currently lack efficient treatments. The mechanisms contributing to normal and impaired alveolar growth and repair are incompletely understood. Axonal guidance cues (AGC) are molecules that guide the outgrowth of axons to their targets. Among these AGCs, members of the Ephrin family also promote angiogenesis, cell migration, and organogenesis outside the nervous system. The role of Ephrins during alveolar growth and repair is unknown. We hypothesized that EphrinB2 promotes alveolar development and repair. We used in vitro and in vivo manipulation of EphrinB2 signaling to assess the role of this AGC during normal and impaired lung development. In vivo EphrinB2 knockdown using intranasal siRNA during the postnatal stage of alveolar development in rats arrested alveolar and vascular growth. In a model of O(2)-induced arrested alveolar growth in newborn rats, air space enlargement, loss of lung capillaries, and pulmonary hypertension were associated with decreased lung EphrinB2 and receptor EphB4 expression. In vitro, EphrinB2 preserved alveolar epithelial cell viability in O(2), decreased O(2)-induced alveolar epithelial cell apoptosis, and accelerated alveolar epithelial cell wound healing, maintained lung microvascular endothelial cell viability, and proliferation and vascular network formation. In vivo, treatment with intranasal EphrinB2 decreased alveolar epithelial and endothelial cell apoptosis, preserved alveolar and vascular growth in hyperoxic rats, and attenuated pulmonary hypertension. The AGC EphrinB2 may be a new therapeutic target for lung repair and pulmonary hypertension.

In Vitro Alterations Do Not Reflect a Requirement for Host Cell Cycle Progression during Plasmodium Liver Stage Infection

PubMed Central

Hanson, Kirsten K.; March, Sandra; Ng, Shengyong; Bhatia, Sangeeta N.

2014-01-01

Prior to invading nonreplicative erythrocytes, Plasmodium parasites undergo their first obligate step in the mammalian host inside hepatocytes, where each sporozoite replicates to generate thousands of merozoites. While normally quiescent, hepatocytes retain proliferative capacity and can readily reenter the cell cycle in response to diverse stimuli. Many intracellular pathogens, including protozoan parasites, manipulate the cell cycle progression of their host cells for their own benefit, but it is not known whether the hepatocyte cell cycle plays a role during Plasmodium liver stage infection. Here, we show that Plasmodium parasites can be observed in mitotic hepatoma cells throughout liver stage development, where they initially reduce the likelihood of mitosis and ultimately lead to significant acquisition of a binucleate phenotype. However, hepatoma cells pharmacologically arrested in S phase still support robust and complete Plasmodium liver stage development, which thus does not require cell cycle progression in the infected cell in vitro. Furthermore, murine hepatocytes remain quiescent throughout in vivo infection with either Plasmodium berghei or Plasmodium yoelii, as do Plasmodium falciparum-infected primary human hepatocytes, demonstrating that the rapid and prodigious growth of liver stage parasites is accomplished independent of host hepatocyte cell cycle progression during natural infection. PMID:25416236

The Analysis of Crack Growth Initiation, Propagation, and Arrest in Flawed Ship Structures Subjected to Dynamic Loading

DTIC Science & Technology

1984-08-10

most current efforts in EPFM are focused on the application of the J-resistance curve to predict crack initiation and fracture instability. However...element code FRACDYN, which has since been used to solve a variety of problems related to the Navy, NRC, and several industrial applications . Of...that this parameter remains constant during elastic-plastic stable crack growth--see Reference (9). This fact, together with its ease of application

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. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

MazEF toxin-antitoxin proteins alter Escherichia coli cell morphology and infrastructure during persister formation and regrowth.

PubMed

Cho, Junho; Carr, Anita Nicole; Whitworth, Lisa; Johnson, Brent; Wilson, Kevin Scott

2017-03-01

When exposed to antibiotics, many bacteria respond by activating intracellular 'toxin' proteins, which arrest cell growth and induce formation of persister cells that survive antibiotics. After antibiotics are removed, persisters can regrow by synthesizing 'antitoxin' proteins that sequester toxin proteins. In Escherichia coli, MazE antitoxin sequesters the activity of MazF toxin, which extensively cleaves cellular RNAs. Although the functions of MazEF proteins are well characterized, there is surprisingly little known about their effects on cell structure. Here, using a combination of microscopy techniques, we visualized the effects of MazEF and three bactericidal antibiotics on E. coli cell morphology and infrastructure. When ectopically expressed in E. coli, MazF temporarily stalled cell growth and induced persister formation, but only mildly elevated DNA mutagenesis. Viewed by electron microscopy, MazF-expressing persister cells were arrested in cell growth and division. Their chromosomal DNAs were compacted into thread-like structures. Their ribosomes were excluded from their nucleoids. After exposure to ciprofloxacin, persister regrowth was activated by MazE. Cell division remained inhibited while cells became extraordinarily elongated, then divided multiple times during stationary growth phase. This extreme filamentation during persister regrowth was unique to ciprofloxacin-treated persisters, likely caused by inhibition of cell division during regrowth, and was not observed with kanamycin-treated persisters.

Long Term Exposure to Polyphenols of Artichoke (Cynara scolymus L.) Exerts Induction of Senescence Driven Growth Arrest in the MDA-MB231 Human Breast Cancer Cell Line.

PubMed

Mileo, Anna Maria; Di Venere, Donato; Abbruzzese, Claudia; Miccadei, Stefania

2015-01-01

Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associated β-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16(INK4a) and p21(Cip1/Waf1) in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

Long Term Exposure to Polyphenols of Artichoke (Cynara scolymus L.) Exerts Induction of Senescence Driven Growth Arrest in the MDA-MB231 Human Breast Cancer Cell Line

PubMed Central

Di Venere, Donato

2015-01-01

Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associated β-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16INK4a and p21Cip1/Waf1 in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy. PMID:26180585

Notch signaling is a potent inducer of growth arrest and apoptosis in a wide range of B-cell malignancies

PubMed Central

Zweidler-McKay, Patrick A.; He, Yiping; Xu, Lanwei; Rodriguez, Carlos G.; Karnell, Fredrick G.; Carpenter, Andrea C.; Aster, Jon C.; Allman, David; Pear, Warren S.

2005-01-01

Although Notch receptor expression on malignant B cells is widespread, the effect of Notch signaling in these cells is poorly understood. To investigate Notch signaling in B-cell malignancy, we assayed the effect of Notch activation in multiple murine and human B-cell tumors, representing both immature and mature subtypes. Expression of constitutively active, truncated forms of the 4 mammalian Notch receptors (ICN1-4) inhibited growth and induced apoptosis in both murine and human B-cell lines but not T-cell lines. Similar results were obtained in human precursor B-cell acute lymphoblastic leukemia lines when Notch activation was achieved by coculture with fibroblasts expressing the Notch ligands Jagged1 or Jagged2. All 4 truncated Notch receptors, as well as the Jagged ligands, induced Hes1 transcription. Retroviral expression of Hairy/Enhancer of Split-1 (Hes1) recapitulated the Notch effects, suggesting that Hes1 is an important mediator of Notch-induced growth arrest and apoptosis in B cells. Among the B-cell malignancies that were susceptible to Notch-mediated growth inhibition/apoptosis were mature B-cell and therapy-resistant B-cell malignancies, including Hodgkin, myeloma, and mixed-lineage leukemia (MLL)–translocated cell lines. These results suggest that therapies capable of activating Notch/Hes1 signaling may have therapeutic potential in a wide range of human B-cell malignancies. PMID:16118316

Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC-4 cells.

PubMed

Chou, Guan-Ling; Peng, Shu-Fen; Liao, Ching-Lung; Ho, Heng-Chien; Lu, Kung-Wen; Lien, Jin-Cherng; Fan, Ming-Jen; La, Kuang-Chi; Chung, Jing-Gung

2018-02-01

Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti-cancer activities. Herein, we investigated the anti-oral cancer activity of casticin on SCC-4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca 2+ production, levels of ΔΨ m and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G 2 /M phase arrest in SCC-4 cells. Casticin promoted ROS and Ca 2+ productions, decreases the levels of ΔΨ m , promoted caspase-3, -8, and -9 activities in SCC-4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC-4 cells. In conclusion, casticin decreased cell number through G 2 /M phase arrest and the induction of cell apoptosis through caspase- and mitochondria-dependent pathways in SCC-4 cells. © 2017 Wiley Periodicals, Inc.

Monitoring substrate enables real-time regulation of a protein localization pathway.

PubMed

Ito, Koreaki; Mori, Hiroyuki; Chiba, Shinobu

2018-06-01

Protein localization machinery supports cell survival and physiology, suggesting the potential importance of its expression regulation. Here, we summarize a remarkable scheme of regulation, which allows real-time feedback regulation of the machinery expression. A class of regulatory nascent polypeptides, called monitoring substrates, undergoes force-sensitive translation arrest. The resulting ribosome stalling on the mRNA then affects mRNA folding to expose the ribosome-binding site of the downstream target gene and upregulate its translation. The target gene encodes a component of the localization machinery, whose physical action against the monitoring substrate leads to arrest cancellation. Thus, this scheme of feedback loop allows the cell to adjust the amount of the machinery to correlate inversely with the effectiveness of the process at a given moment. The system appears to have emerged late in evolution, in which a narrow range of organisms selected a distinct monitoring substrate-machinery combination. Currently, regulatory systems of SecM-SecA, VemP-SecDF2 and MifM-YidC2 are known to occur in different bacterial species.

Brain protection in aortic arch aneurysm: antegrade or retrograde?

PubMed

Harky, Amer; Fok, Matthew; Bashir, Mohamad; Estrera, Anthony L

2018-01-03

During open aortic arch repair, there is an interruption of cerebral perfusion and to prevent neurological sequelae, the hypothermic circulatory arrest has been established to provide sufficient brain protection coupled with adjuncts including retrograde and antegrade cerebral perfusion. To date, brain protection during open aortic arch repair is a contested topic as to which provides superior brain protection with little evidence existing to suggest supremacy of one modality over the other. This article reviews current literature reflecting on key and emerging studies in brain protection and their associated outcomes in patients undergoing open aortic arch surgery.

Myocardial infarction and subsequent death in a patient undergoing robotic prostatectomy.

PubMed

Thompson, Judy

2009-10-01

A 52-year-old patient, ASA physical status IV, undergoing a radical prostatectomy for cancer with a robotic system had a cardiac arrest 3 hours into the case. All attempts to resuscitate were unsuccessful, and several hours later he was pronounced dead. Underlying patient comorbidity and procedural issues contributed to the patient's death. The patient had a history of coronary artery disease that required the placement of drug-eluting stents 2 years before this surgical procedure. The preoperative cardiac evaluation and pharmacological management of patients with drug-eluting coronary stents are reviewed. There are a number of positional and technical considerations for patients undergoing robotic surgical procedures, especially in relation to the requirement of low-lithotomy and steep Trendelenburg positions. The cardiac and respiratory systems are especially vulnerable to the extreme and lengthy head-down position. The needed positioning, combined with the problems associated with insufflation, presents a unique challenge in anesthetic management. This course reviews the current literature on the surgical implications for patients with drug-eluting stents and the physiologic factors related to position and pneumoperitoneum and their associated stressors. By using a review of the contemporary literature, a best-evidence approach to anesthetic management is reviewed.

New labor management guidelines and changes in cesarean delivery patterns.

PubMed

Rosenbloom, Joshua I; Stout, Molly J; Tuuli, Methodius G; Woolfolk, Candice L; López, Julia D; Macones, George A; Cahill, Alison G

2017-12-01

In 2010 the Consortium on Safe Labor published labor curves. It was proposed that the rate of cesarean delivery could be lowered by avoiding the diagnosis of arrest of dilation before 6 cm. However, there is little information on the uptake of the guidelines and on changes in cesarean delivery rates that may have occurred. The objective of the study was to test the following hypotheses: (1) among patients laboring at term, rates of arrest of dilation disorders have decreased, leading to a decrease in the rate of cesarean delivery; (2) in the second stage, pushing duration prior to diagnosis of arrest of descent has increased, also leading to a reduction in the rate of cesarean delivery for this indication. As a secondary aim, we investigated changes in maternal and neonatal morbidity. This was a secondary analysis of a prospective cohort study of all patients presenting at ≥37 weeks' gestation from 2010 through 2014 with a nonanomalous vertex singleton and no prior history of cesarean delivery. Rates of cesarean delivery, arrest of dilation, and changes in rates of maternal and neonatal morbidity were calculated in crude and adjusted models. Cervical dilation at diagnosis of the arrest of dilation, time spent at the maximal dilation prior to diagnosis of arrest of dilation, and time in the second stage prior to the diagnosis of arrest of descent were compared over the study period. There were 7845 eligible patients. The cesarean delivery rate in 2010 was 15.8% and, in 2014, 17.7% (P trend = .51). In patients undergoing cesarean delivery for the arrest of dilation, the median cervical dilation at the time of cesarean delivery was at 5.5 cm in 2010 and 6.0 cm in 2014 (P trend = .94). In these patients, there was an increase in the time spent at last dilation: 3.8 hours in 2010 to 5.2 hours in 2014 (P trend = .02). There was no change in the frequency of patients diagnosed with the arrest of dilation at <6 cm: 51.4% in 2010 and 48.6% in 2014 (P trend = .56). However, in these patients, the median time spent at the last cervical dilation was 4.0 hours in 2010 and 6.7 hours in 2014 (P trend = .046). There were 206 cesarean deliveries for the arrest of descent. The median pushing time in these patients increased in multiparous patients from 1.1 hours in 2010 to 3.4 hours in 2014 (P trend = .009); in nulliparous patients these times were 2.7 hours in 2010 and 3.8 hours in 2014 (P trend = .09). There was a significant trend toward increasing adverse neonatal and maternal outcomes (P < .001 for each). The adjusted odds ratio for adverse maternal outcome for 2014 compared with 2010 was 1.66 (95% confidence interval, 1.27-2.17); however, considering only transfusion, hemorrhage, or infection, there was no difference (P trend = .96). The adjusted odds ratio of adverse neonatal outcome in 2014 compared with 2010 was 1.80 (95% confidence interval, 1.36-2.36). Despite significant changes in labor management that have occurred over the initial years since publication of the new labor curves and associated guidelines, the primary cesarean delivery rate was not reduced and there has been an increase in maternal and neonatal morbidity in our institution. A randomized controlled trial is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

EFFECT OF ARSENICALS ON ULTRAVIOLET-RADIATION-INDUCED GROWTH ARREST AND RELATED SIGNALING EVENTS IN HUMAN KERATINOCYTES

EPA Science Inventory

The molecular mechanisms mediating arsenic-induced carcinogenesis are not well understood. The role of confounding factors such as ultraviolet radiation (UV), add another level of complexity to the study of arsenic carcinogenesis and the cancer risk assessment to humans. We hypot...

Strain Rate Sensitivity of Polymer-Matrix Composites under Mode I delamination

DTIC Science & Technology

1990-12-01

unstable growth system requires two values. In reality , the fracture toughness may vary along the length of the specimen due to strain rate effects...18 M. F. Kanninen. An Augmented Double Cantilever Beam Model for Studying Crack Propagation and Arrest. International Journal of Fracture. Vol. 9

Dynamical arrest with zero complexity: The unusual behavior of the spherical Blume-Emery-Griffiths disordered model

NASA Astrophysics Data System (ADS)

Rainone, Corrado; Ferrari, Ulisse; Paoluzzi, Matteo; Leuzzi, Luca

2015-12-01

The short- and long-time dynamics of model systems undergoing a glass transition with apparent inversion of Kauzmann and dynamical arrest glass transition lines is investigated. These models belong to the class of the spherical mean-field approximation of a spin-1 model with p -body quenched disordered interaction, with p >2 , termed spherical Blume-Emery-Griffiths models. Depending on temperature and chemical potential the system is found in a paramagnetic or in a glassy phase and the transition between these phases can be of a different nature. In specific regions of the phase diagram coexistence of low-density and high-density paramagnets can occur, as well as the coexistence of spin-glass and paramagnetic phases. The exact static solution for the glassy phase is known to be obtained by the one-step replica symmetry breaking ansatz. Different scenarios arise for both the dynamic and the thermodynamic transitions. These include: (i) the usual random first-order transition (Kauzmann-like) for mean-field glasses preceded by a dynamic transition, (ii) a thermodynamic first-order transition with phase coexistence and latent heat, and (iii) a regime of apparent inversion of static transition line and dynamic transition lines, the latter defined as a nonzero complexity line. The latter inversion, though, turns out to be preceded by a dynamical arrest line at higher temperature. Crossover between different regimes is analyzed by solving mode-coupling-theory equations near the boundaries of paramagnetic solutions and the relationship with the underlying statics is discussed.

p21-activated kinase 1: PAK'ed with potential.

PubMed

Ong, Christy C; Jubb, Adrian M; Zhou, Wei; Haverty, Peter M; Harris, Adrian L; Belvin, Marcia; Friedman, Lori S; Koeppen, Hartmut; Hoeflich, Klaus P

2011-06-01

The p21-activated kinases (PAKs) are central players in growth factor signaling networks and morphogenetic processes that control proliferation, cell polarity, invasion and actin cytoskeleton organization. This raises the possibility that interfering with PAK activity may produce significant anti-tumor activity. In this perspective, we summarize recent data concerning the contribution of the PAK family member, PAK1, in growth factor signaling and tumorigenesis. We further discuss mechanisms by which inhibition of PAK1 can arrest tumor growth and promote cell apoptosis, and the types of cancers in which PAK1 inhibition may hold promise.

Molecular Mechanism of Action of Genistein and Related Phytoestrogens in Estrogen-Receptor Dependent and Independent Growth of Breast Cancer Cells

DTIC Science & Technology

1999-07-01

quercetin inhibited ER-negative MDA-MB-468 breast cancer cell growth with 1050 values of 8.8 and 18.1 Micronmeter, respectively. The other compounds...were less effective. The mechanism of growth inhibition by genistein and quercetin involved G2/M cell cycle arrest, changes in cyclin B1 levels and...apoptosis. Our results indicate that genistein and quercetin may be useful in the treatment of ER-negative tumors. Results of our studies on MDA-MB-468 cells have been documented and submitted for publication.

Vitamin K2 and cotylenin A synergistically induce monocytic differentiation and growth arrest along with the suppression of c-MYC expression and induction of cyclin G2 expression in human leukemia HL-60 cells.

PubMed

Maniwa, Yasuhisa; Kasukabe, Takashi; Kumakura, Shunichi

2015-08-01

Although all-trans retinoic acid (ATRA) is a standard and effective drug used for differentiation therapy in acute promyelocytic leukemia, ATRA-resistant leukemia cells ultimately emerge during this treatment. Therefore, the development of new drugs or effective combination therapy is urgently needed. We demonstrate that the combined treatment of vitamin K2 and cotylenin A synergistically induced monocytic differentiation in HL-60 cells. This combined treatment also synergistically induced NBT-reducing activity and non-specific esterase-positive cells as well as morphological changes to monocyte/macrophage-like cells. Vitamin K2 and cotylenin A cooperatively inhibited the proliferation of HL-60 cells in short-term and long-term cultures. This treatment also induced growth arrest at the G1 phase. Although 5 µg/ml cotylenin A or 5 µM vitamin K2 alone reduced c-MYC gene expression in HL-60 cells to approximately 45% or 80% that of control cells, respectively, the combined treatment almost completely suppressed c-MYC gene expression. We also demonstrated that the combined treatment of vitamin K2 and cotylenin A synergistically induced the expression of cyclin G2, which had a positive effect on the promotion and maintenance of cell cycle arrest. These results suggest that the combination of vitamin K2 and cotylenin A has therapeutic value in the treatment of acute myeloid leukemia.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yiting; Wu, Dan; Xia, Fengjie

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 cellmore » 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. - Highlights: • High expression of HDAC9 correlates with poor patient prognosis. • Downregulation of HDAC9 inhibits cell proliferation in retinoblastoma cells. • Downregulation of HDAC9 induces cell cycle arrest at G1 phase in retinoblastoma cells. • Downregulation of HDAC9 suppresses tumor growth in nude mice.« less

Enterolactone induces G1-phase cell cycle arrest in non-small cell lung cancer cells by down-regulating cyclins and cyclin-dependent kinases

PubMed Central

Chikara, Shireen; Lindsey, Kaitlin; Dhillon, Harsharan; Mamidi, Sujan; Kittilson, Jeffrey; Christofidou-Solomidou, Melpo; Reindl, Katie M.

2017-01-01

Flaxseed is a rich source of the plant lignan secoisolariciresinol diglucoside (SDG) which is metabolized into mammalian lignans enterodiol (ED) and enterolactone (EL) in the digestive tract. The anti-cancer properties of these lignans have been demonstrated for various cancer types, but have not been studied for lung cancer. In this study we investigated the anti-cancer effects of EL for several non-small cell lung cancer (NSCLC) cell lines of various genetic backgrounds. EL inhibited the growth of A549, H441, and H520 lung cancer cells in concentration- and time-dependent manners. The anti-proliferative effects of EL for lung cancer cells were not due to enhanced cell death, but rather due to G1-phase cell cycle arrest. Molecular studies revealed that EL- decreased mRNA or protein expression levels of the G1-phase promoters cyclin D1, cyclin E, cyclin-dependent kinases (CDK)-2, -4, and -6, and p-cdc25A; decreased phosphorylated retinoblastoma (p-pRb) protein levels; and simultaneously increased levels of p21WAF1/CIP1, a negative regulator of the G1-phase. The results suggest that EL inhibits the growth of NSCLC cell lines by down-regulating G1-phase cyclins and CDKs, and up-regulating p21WAF1/CIP1, which leads to G1-phase cell cycle arrest. Therefore, EL may hold promise as an adjuvant treatment for lung cancer therapy. PMID:28323486

Enterolactone Induces G1-phase Cell Cycle Arrest in Nonsmall Cell Lung Cancer Cells by Downregulating Cyclins and Cyclin-dependent Kinases.

PubMed

Chikara, Shireen; Lindsey, Kaitlin; Dhillon, Harsharan; Mamidi, Sujan; Kittilson, Jeffrey; Christofidou-Solomidou, Melpo; Reindl, Katie M

2017-01-01

Flaxseed is a rich source of the plant lignan secoisolariciresinol diglucoside (SDG), which is metabolized into mammalian lignans enterodiol (ED) and enterolactone (EL) in the digestive tract. The anticancer properties of these lignans have been demonstrated for various cancer types, but have not been studied for lung cancer. In this study, we investigated the anticancer effects of EL for several nonsmall cell lung cancer (NSCLC) cell lines of various genetic backgrounds. EL inhibited the growth of A549, H441, and H520 lung cancer cells in concentration- and time-dependent manners. The antiproliferative effects of EL for lung cancer cells were not due to enhanced cell death, but rather due to G 1 -phase cell cycle arrest. Molecular studies revealed that EL decreased mRNA or protein expression levels of the G 1 -phase promoters cyclin D1, cyclin E, cyclin-dependent kinases (CDK)-2, -4, and -6, and p-cdc25A; decreased phosphorylated retinoblastoma (p-pRb) protein levels; and simultaneously increased levels of p21 WAF1/CIP1 , a negative regulator of the G 1 phase. The results suggest that EL inhibits the growth of NSCLC cell lines by downregulating G 1 -phase cyclins and CDKs, and upregulating p21 WAF1/CIP1 , which leads to G 1 -phase cell cycle arrest. Therefore, EL may hold promise as an adjuvant treatment for lung cancer therapy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varley, Claire; Hill, Gemma; Pellegrin, Stephanie

Regeneration of the urothelium is rapid and effective in order to maintain a barrier to urine following tissue injury. Whereas normal human urothelial (NHU) cells are mitotically quiescent and G0 arrested in situ, they rapidly enter the cell cycle upon seeding in primary culture and show reversible growth arrest at confluency. We have used this as a model to investigate the role of EGF receptor signaling in urothelial regeneration and wound-healing. Transcripts for HER-1, HER-2, and HER-3 were expressed by quiescent human urothelium in situ. Expression of HER-1 was upregulated in proliferating cultures, whereas HER-2 and HER-3 were more associatedmore » with a growth-arrested phenotype. NHU cells could be propagated in the absence of exogenous EGF, but autocrine signaling through HER-1 via the MAPK and PI3-kinase pathways was essential for proliferation and migration during urothelial wound repair. HB-EGF was expressed by urothelium in situ and HB-EGF, epiregulin, TGF-{alpha}, and amphiregulin were expressed by proliferating NHU cells. Urothelial wound repair in vitro was attenuated by neutralizing antibodies against HER-1 ligands, particularly amphiregulin. By contrast, the same ligands applied exogenously promoted migration, but inhibited proliferation, implying that HER-1 ligands provoke differential effects in NHU cells depending upon whether they are presented as soluble or juxtacrine ligands. We conclude that proliferation and migration during wound healing in NHU cells are mediated through an EGFR autocrine signalling loop and our results implicate amphiregulin as a key mediator.« less

Proteomic analysis of the molecular response of Raji cells to maslinic acid treatment.

PubMed

Yap, W H; Khoo, K S; Lim, S H; Yeo, C C; Lim, Y M

2012-01-15

Maslinic acid, a natural pentacyclic triterpene has been shown to inhibit growth and induce apoptosis in some tumour cell lines. We studied the molecular response of Raji cells towards maslinic acid treatment. A proteomics approach was employed to identify the target proteins. Seventeen differentially expressed proteins including those involved in DNA replication, microtubule filament assembly, nucleo-cytoplasmic trafficking, cell signaling, energy metabolism and cytoskeletal organization were identified by MALDI TOF-TOF MS. The down-regulation of stathmin, Ran GTPase activating protein-1 (RanBP1), and microtubule associated protein RP/EB family member 1 (EB1) were confirmed by Western blotting. The study of the effect of maslinic acid on Raji cell cycle regulation showed that it induced a G1 cell cycle arrest. The differential proteomic changes in maslinic acid-treated Raji cells demonstrated that it also inhibited expression of dUTPase and stathmin which are known to induce early S and G2 cell cycle arrests. The mechanism of maslinic acid-induced cell cycle arrest may be mediated by inhibiting cyclin D1 expression and enhancing the levels of cell cycle-dependent kinase (CDK) inhibitor p21 protein. Maslinic acid suppressed nuclear factor-kappa B (NF-κB) activity which is known to stimulate expression of anti-apoptotic and cell cycle regulatory gene products. These results suggest that maslinic acid affects multiple signaling molecules and inhibits fundamental pathways regulating cell growth and survival in Raji cells. Copyright © 2011 Elsevier GmbH. All rights reserved.

DAT-230, a Novel Microtubule Inhibitor, Induced Aberrant Mitosis and Apoptosis in SGC-7901 Cells.

PubMed

Qiao, Foxiao; Zuo, Daiying; Wang, Haifeng; Li, Zengqiang; Qi, Huan; Zhang, Weige; Wu, Yingliang

2013-01-01

2-Methoxy-5-(2-(3,4,5-trimethoxyphenyl)thiophen-3-yl) aniline (DAT-230) is a novel synthesized compound of combretastatin-A-4 derivative with more stability. The present study is to investigate its anti-tumor activity and molecular mechanisms in human gastric adenocarcinoma SGC-7901 cells. DAT-230 inhibited SGC-7901 cells growth. The treatment of DAT-230 resulted in microtubule de-polymerization and G2/M phase arrest. Besides the accumulation and translocation of Cyclin B1, reduction of p-14/15-cdc2 and mitosis delay denoted the Cyclin B1-cdc2 complex active and M phase arrest in SGC-7901 cells treated with DAT-230. Mitochondria pathway participated in apoptosis after G2/M arrest in SGC-7901 cells treated with DAT-230, which was characterized by DNA fragmentation, cleavage of poly(ADP-ribose) polymerase (PARP), activation of caspase-3 and caspase-9, changes of Bcl-2 and Bax expression, decrease of mitochondrial membrane potential and release of cytochrome c from mitochondria. In vivo, DAT-230 delayed tumor growth in BALB/c nude mice with human gastric adenocarcinoma xenografts. Besides apoptosis was detected with terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay in tumor tissue. In conclusion, DAT-230 is a promising microtubule inhibitor with great anti-tumor activity to SGC-7901, in vitro and in vivo. Its potential to be a candidate of anti-cancer agent is worth of being further investigated.

Multiple Mechanisms Are Involved in 6-Gingerol-Induced Cell Growth Arrest and Apoptosis in Human Colorectal Cancer Cells

PubMed Central

Lee, Seong-Ho; Cekanova, Maria; Baek, Seung Joon

2008-01-01

6-Gingerol, a natural product of ginger, has been known to possess anti-tumorigenic and pro-apoptotic activities. However, the mechanisms by which it prevents cancer are not well understood in human colorectal cancer. Cyclin D1 is a proto-oncogene that is overexpressed in many cancers and plays a role in cell proliferation through activation by β-catenin signaling. Nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and anti-tumorigenic properties. In the present study, we examined whether 6-gingerol influences cyclin D1 and NAG-1 expression and determined the mechanisms by which 6-gingerol affects the growth of human colorectal cancer cells in vitro. 6-Gingerol treatment suppressed cell proliferation and induced apoptosis and G1 cell cycle arrest. Subsequently, 6-gingerol suppressed cyclin D1 expression and induced NAG-1 expression. Cyclin D1 suppression was related to inhibition of β-catenin translocation and cyclin D1 proteolysis. Furthermore, experiments using inhibitors and siRNA transfection confirm the involvement of the PKCε and glycogen synthase kinase (GSK)-3β pathways in 6-gingerol-induced NAG-1 expression. The results suggest that 6-gingerol stimulates apoptosis through upregulation of NAG-1 and G1 cell cycle arrest through downregulation of cyclin D1. Multiple mechanisms appear to be involved in 6-gingerol action, including protein degradation as well as β-catenin, PKCε, and GSK-3β pathways. PMID:18058799

Type-1-cytokines synergize with oncogene inhibition to induce tumor growth arrest

PubMed Central

Acquavella, Nicolas; Clever, David; Yu, Zhiya; Roelke-Parker, Melody; Palmer, Douglas C.; Xi, Liqiang; Pflicke, Holger; Ji, Yun; Gros, Alena; Hanada, Ken-ichi; Goldlust, Ian S.; Mehta, Gautam U.; Klebanoff, Christopher A.; Crompton, Joseph G.; Sukumar, Madhusudhanan; Morrow, James J.; Franco, Zulmarie; Gattinoni, Luca; Liu, Hui; Wang, Ena; Marincola, Francesco; Stroncek, David F.; Lee, Chyi-Chia R.; Raffeld, Mark; Bosenberg, Marcus W.; Roychoudhuri, Rahul; Restifo, Nicholas P.

2014-01-01

Both targeted inhibition of oncogenic driver mutations and immune-based therapies show efficacy in treatment of patients with metastatic cancer but responses can be either short-lived or incompletely effective. Oncogene inhibition can augment the efficacy of immune-based therapy but mechanisms by which these two interventions might cooperate are incompletely resolved. Using a novel transplantable BRAFV600E-mutant murine melanoma model (SB-3123), we explore potential mechanisms of synergy between the selective BRAFV600E inhibitor vemurafenib and adoptive cell transfer (ACT)-based immunotherapy. We found that vemurafenib cooperated with ACT to delay melanoma progression without significantly affecting tumor infiltration or effector function of endogenous or adoptively transferred CD8+ T cells as previously observed. Instead, we found that the T-cell cytokines IFNγ and TNFα synergized with vemurafenib to induce cell-cycle arrest of tumor cells in vitro. This combinatorial effect was recapitulated in human melanoma-derived cell lines and was restricted to cancers bearing a BRAFV600E-mutation. Molecular profiling of treated SB-3123 indicated that the provision of vemurafenib promoted the sensitization of SB-3123 to the anti-proliferative effects of T-cell effector cytokines. The unexpected finding that immune cytokines synergize with oncogene inhibitors to induce growth arrest have major implications for understanding cancer biology at the intersection of oncogenic and immune signaling and provides a basis for design of combinatorial therapeutic approaches for patients with metastatic cancer. PMID:25358764

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

PubMed

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

2006-12-01

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

Enforced expression of the c-myc oncogene inhibits cell differentiation by precluding entry into a distinct predifferentiation state in G/sub 0//G/sub 1/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freytag, S.O.

1988-04-01

A broad base of data has implicated a role for the c-myc proto-oncogene in the control of the cell cycle and cell differentiation. To further define the role of myc in these processes, the authors examined the effect of enforced myc expression on several events that are thought to be important steps leading to the terminally differentiated state: (i) the ability to arrest growth in G/sub 0//G/sub 1/, (ii) the ability to replicate the genome upon initiation of the differentiation program, and (iii) the ability to loose responsiveness to mitogens and withdraw from the cell cycle. 3T3-L1 preadipocyte cell linesmore » expressing various levels of myc mRNA were established by transfection with a recombinant myc gene under the transcriptional control of the Rous sarcoma virus (RSV) promoter. Cells that expressed high constitutive levels of pRSV myc mRNA arrested in G/sub 0//G/sub 1/ at densities similar to those of normal cells at confluence. Upon initiation of the differentiation program, such cells traversed the cell cycle with kinetics similar to those of normal cells and subsequently arrested in G/sub 0//G/sub 1/. Thus, enforced expression of myc had no effect on the ability of cells to arrest growth in G/sub 0//G/sub 1/ or to replicate the genome upon initiation of the differentiation program. Cells were then tested for their ability to reenter the cell cycle upon exposure to high concentrations of serum and for their capacity to differentiate. In contrast to normal cells, cells expressing high constitutive levels of myc RNA reentered the cell cycle when challenged with 30% serum and failed to terminally differentiate.« less

Cryptotanshinone induces cell cycle arrest and apoptosis through the JAK2/STAT3 and PI3K/Akt/NFκB pathways in cholangiocarcinoma cells.

PubMed

Ke, Fayong; Wang, Zheng; Song, Xiaoling; Ma, Qiang; Hu, Yunping; Jiang, Lin; Zhang, Yijian; Liu, Yingbin; Zhang, Yong; Gong, Wei

2017-01-01

Cholangiocarcinoma (CCA) is the most common biliary tract malignancy in the world with high resistance to current chemotherapies and extremely poor prognosis. The main objective of this study was to investigate the inhibitory effects of cryptotanshinone (CTS), a natural compound isolated from Salvia miltiorrhiza Bunge , on CCA both in vitro and in vivo and to explore the underlying mechanisms of CTS-induced apoptosis and cell cycle arrest. The anti-tumor activity of CTS on HCCC-9810 and RBE cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and colony forming assays. Cell cycle changes were detected by flow cytometric analysis. Apoptosis was detected by annexin V/propidium iodide double staining and Hoechst 33342 staining assays. The efficacy of CTS in vivo was evaluated using a HCCC-9810 xenograft model in athymic nude mice. The expression of key proteins involved in cell apoptosis and signaling pathway in vitro was analyzed by Western blot analysis. CTS induced potent growth inhibition, S-phase arrest, apoptosis, and colony-forming inhibition in HCCC-9810 and RBE cells in a dose-dependent manner. Intraperitoneal injection of CTS (0, 10, or 25 mg/kg) for 4 weeks significantly inhibited the growth of HCCC-9810 xenografts in athymic nude mice. CTS treatment induced S-phase arrest with a decrease of cyclin A1 and an increase of cyclin D1 protein level. Bcl-2 expression was downregulated remarkably, while Bax expression was increased after apoptosis occurred. Additionally, the activation of JAK2/STAT3 and PI3K/Akt/NFκB was significantly inhibited in CTS-treated CCA cells. CTS induced CCA cell apoptosis by suppressing both the JAK2/STAT3 and PI3K/Akt/NFκB signaling pathways and altering the expression of Bcl-2/Bax family, which was regulated by these two signaling pathways. CTS may serve as a potential therapeutic agent for CCA.

Biological Effects of Activating Distinct ErbB Receptor Dimers in Polarized Growth Arrested Epithelia

DTIC Science & Technology

2006-09-01

deregulating the function of Par protein complex, we made the unexpected observation that overexpression of Par6 induced growth- factor independent...predisposition factors for human cancer [8] and the human papillomavirus protein E6, targets scribble for degradation[9]. It has also been shown that Par6...vivo and thus is an excellent model to study the important factors in the initiation of the oncogenic process. However, activation of ErbB1 does not

Analysis of Crack Arrest Toughness.

DTIC Science & Technology

1988-01-15

kl,. and that the microstructural features that effect "eligibility" may have a modest effect on K,. 1953 to 1955 he sered in the Titani im Section of...ductile fracture criterion, computations which assumed that the 6-Aa history was the same for rapid fracture as it was for stable crack growth agree...around the crack tip [25]. The 8-Aa history , used as the fracture criterion for the first 4 mm of growth in the dynamic analysis, was obtained from the

Wip1 knockout inhibits the proliferation and enhances the migration of bone marrow mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Yiting; State Key Laboratory of Animal Nutrition and Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193; Liu, Lan

2015-06-10

Mesenchymal stem cells (MSCs), a unique population of multipotent adult progenitor cells originally found in bone marrow (BM), are extremely useful for multifunctional therapeutic approaches. However, the growth arrest and premature senescence of MSCs in vitro prevent the in-depth characterization of these cells. In addition, the regulatory factors involved in MSCs migration remain largely unknown. Given that protein phosphorylation is associated with the processes of MSCs proliferation and migration, we focused on wild-type p53-inducible phosphatase-1 (Wip1), a well-studied modulator of phosphorylation, in this study. Our results showed that Wip1 knockout significantly inhibited MSCs proliferation and induced G2-phase cell-cycle arrest bymore » reducing cyclinB1 expression. Compared with WT-MSCs, Wip1{sup −/−} MSCs displayed premature growth arrest after six passages in culture. Transwell and scratch assays revealed that Wip1{sup −/−} MSCs migrate more effectively than WT-MSCs. Moreover, the enhanced migratory response of Wip1{sup −/−} MSCs may be attributed to increases in the induction of Rac1-GTP activity, the pAKT/AKT ratio, the rearrangement of filamentous-actin (f-actin), and filopodia formation. Based on these results, we then examined the effect of treatment with a PI3K/AKT and Rac1 inhibitor, both of which impaired the migratory activity of MSCs. Therefore, we propose that the PI3K/AKT/Rac1 signaling axis mediates the Wip1 knockout-induced migration of MSCs. Our findings indicate that the principal function of Wip1 in MSCs transformation is the maintenance of proliferative capacity. Nevertheless, knocking out Wip1 increases the migratory capacity of MSCs. This dual effect of Wip1 provides the potential for purposeful routing of MSCs. - Highlights: • Wip1 knockout inhibited MSCs proliferation through reducing cyclinB1 expression. • Wip1{sup −/−} MSCs displayed premature growth arrest in vitro after six passages. • Knocking out Wip1 increases the migratory capacity of MSCs. • The PI3K/AKT/Rac1 pathway mediates the Wip1-knockout-induced migration of MSCs. • Overexpression of Wip1 reversed premature senescence and migration of Wip1{sup −/−} MSCs.« less

p14ARF Post-Transcriptional Regulation of Nuclear Cyclin D1 in MCF-7 Breast Cancer Cells: Discrimination between a Good and Bad Prognosis?

PubMed Central

McGowan, Eileen M.; Tran, Nham; Alling, Nikki; Yagoub, Daniel; Sedger, Lisa M.; Martiniello-Wilks, Rosetta

2012-01-01

As part of a cell’s inherent protection against carcinogenesis, p14ARF is upregulated in response to hyperproliferative signalling to induce cell cycle arrest. This property makes p14ARF a leading candidate for cancer therapy. This study explores the consequences of reactivating p14ARF in breast cancer and the potential of targeting p14ARF in breast cancer treatment. Our results show that activation of the p14ARF-p53-p21-Rb pathway in the estrogen sensitive MCF-7 breast cancer cells induces many hallmarks of senescence including a large flat cell morphology, multinucleation, senescence-associated-β-gal staining, and rapid G1 and G2/M phase cell cycle arrest. P14ARF also induces the expression of the proto-oncogene cyclin D1, which is most often associated with a transition from G1-S phase and is highly expressed in breast cancers with poor clinical prognosis. In this study, siRNA knockdown of cyclin D1, p21 and p53 show p21 plays a pivotal role in the maintenance of high cyclin D1 expression, cell cycle and growth arrest post-p14ARF induction. High p53 and p14ARF expression and low p21/cyclin D1 did not cause cell-cycle arrest. Knockdown of cyclin D1 stops proliferation but does not reverse senescence-associated cell growth. Furthermore, cyclin D1 accumulation in the nucleus post-p14ARF activation correlated with a rapid loss of nucleolar Ki-67 protein and inhibition of DNA synthesis. Latent effects of the p14ARF-induced cellular processes resulting from high nuclear cyclin D1 accumulation included a redistribution of Ki-67 into the nucleoli, aberrant nuclear growth (multinucleation), and cell proliferation. Lastly, downregulation of cyclin D1 through inhibition of ER abrogated latent recurrence. The mediation of these latent effects by continuous expression of p14ARF further suggests a novel mechanism whereby dysregulation of cyclin D1 could have a double-edged effect. Our results suggest that p14ARF induced-senescence is related to late-onset breast cancer in estrogen responsive breast cancers and/or the recurrence of more aggressive breast cancer post-therapy. PMID:22860097

Using Growth and Arrest of Richtmyer-Meshkov Instabilities and Lagrangian Simulations to Study High-Rate Material Strength

NASA Astrophysics Data System (ADS)

Prime, Michael; Vaughan, Diane; Preston, Dean; Oro, David; Buttler, William

2013-06-01

Rayleigh-Taylor instabilities have been widely used to study the deviatoric (flow) strength of solids at high strain rates. More recently, experiments applying a supported shock through mating surfaces (Atwood number = 1) with geometrical perturbations have been proposed for studying strength at strain rates up to 107/sec using Richtmyer-Meshkov (RM) instabilities. Buttler et al. [J. Fluid Mech., 2012] recently reported experimental results for RM instability growth but with an unsupported shock applied by high explosives and the geometrical perturbations on the opposite free surface (Atwood number = -1). This novel configuration allowed detailed experimental observation of the instability growth and arrest. We present results and detailed interpretation from numerical simulations of the Buttler experiments on copper. Highly-resolved, two-dimensional simulations were performed using a Lagrangian hydrocode and the Preston-Tonks-Wallace (PTW) strength model. The model predictions show good agreement with the data in spite of the PTW model being calibrated on lower strain rate data. The numerical simulations are used to 1) examine various assumptions previously made in an analytical model, 2) to estimate the sensitivity of such experiments to material strength and 3) to explore the possibility of extracting meaningful strength information in the face of complicated spatial and temporal variations of stress, pressure, and temperature during the experiments.

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

PubMed

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

2017-03-01

The tender leaves of Rubus corchorifolius L. f. have been consumed as tea for drinking in China since ancient times. In this study, a novel ent-kaurane diterpenoid was isolated and identified from R. corchorifolius L. f. leaves as ent-kaur-2-one-16β,17-dihydroxy-acetone-ketal (DEK). DEK suppressed the growth of HCT116 human colon cancer cells with an IC 50 value of 40 ± 0.21 μM, while it did not cause significant growth inhibition on CCD-18Co human colonic myofibroblasts at up to100 μM. Moreover, DEK induced extensive apoptosis and S phase cell cycle arrest in the colon cancer cells. Accordingly, DEK caused profound effects on multiple signaling proteins associated with cell proliferation, cell death, and inflammation. DEK significantly upregulated the expression levels of pro-apoptotic proteins such as cleaved caspase-3, cleaved caspase-9, cleaved PARP, p53, Bax, and tumor suppressor p21 Cip1/Waf1 , downregulated the levels of cell cycle regulating proteins such as cyclinD1, CDK2, and CDK4 and carcinogenic proteins such as EGFR and COX-2, and suppressed the activation of Akt. Overall, our results provide a basis for using DEK as a potential chemopreventive agent against colon carcinogenesis.

SOX4 inhibits GBM cell growth and induces G0/G1 cell cycle arrest through Akt-p53 axis.

PubMed

Zhang, Jing; Jiang, Huawei; Shao, Jiaofang; Mao, Ruifang; Liu, Jie; Ma, Yingying; Fang, Xuefeng; Zhao, Na; Zheng, Shu; Lin, Biaoyang

2014-11-01

SOX4 is a transcription factor required for tissue development and differentiation in vertebrates. Overexpression of SOX4 has been reported in many cancers including glioblastoma multiforme (GBM), however, the underlying mechanism of actions has not been studied. In this study, we investigated the role of SOX4 in GBM. Kaplan-Meier analysis was performed to assess the association between SOX4 expression levels and survival times in primary GBM samples. Cre/lox P system was used to generate gain or loss of SOX4 in GBM cells, and microarray analysis uncovered the regulation network of SOX4 in GBM cells. High SOX4 expression was significantly associated with good prognosis of primary GBMs. SOX4 inhibited the growth of GBM cell line LN229, A172G and U87MG, partly via the activation of p53-p21 signaling and down-regulation of phosphorylated AKT1. Gene expression profiling and subsequent gene ontology analysis showed that SOX4 influenced several key pathways including the Wnt/ beta-catenin and TGF-beta signaling pathways. Our study found that SOX4 acts as a tumor suppressor in GBM cells by induce cell cycle arrest and inhibiting cell growth.

[Inhibitory effect of exogenous insulin-like growth factor binding protein 7 on proliferation of human breast cancer cell line MDA-MB-453 and its mechanism].

PubMed

Yuan, Lei; Fan, Wen-Juan; Yang, Xu-Guang; Rao, Shu-Mei; Song, Jin-Ling; Song, Guo-Hua

2013-10-25

The present study was to investigate the effects of exogenous insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation of human breast cancer cell line MDA-MB-453 and its possible mechanism. By means of MTT method in vitro, the results showed exogenous IGFBP7 inhibited the growth of MDA-MB-453 cells (IC50 of IGFBP7 = 8.49 μg/mL) in time- and concentration-dependent manner. SB203580, p38(MAPK) inhibitor, blocked the anti-proliferative effect of exogenous IGFBP7. The flow cytometry assay showed that exogenous IGFBP7 remarkably induced G0/G1 arrest in MDA-MB-453 cells. The Western blot showed that exogenous IGFBP7 promoted phosphorylation of p38(MAPK), up-regulated expression of p21(CIP1/WAF1), and inhibited phosphorylation of Rb. SB203580 restrained exogenous IGFBP7-induced regulation of p21(CIP1/WAF1) and p-Rb in MDA-MB-453 cells. In conclusion, the present study suggests that exogenous IGFBP7 could activate the p38(MAPK) signaling pathway, upregulate p21(CIP1/WAF1) expression, inhibit phosphorylation of Rb, and finally induce G0/G1 arrest in MDA-MB-453 cells.

Akt interacts directly with Smad3 to regulate the sensitivity to TGF-beta induced apoptosis.

PubMed

Conery, Andrew R; Cao, Yanna; Thompson, E Aubrey; Townsend, Courtney M; Ko, Tien C; Luo, Kunxin

2004-04-01

Transforming growth factor beta (TGF-beta) induces both apoptosis and cell-cycle arrest in some cell lines, but only growth arrest in others. It is not clear how this differential response to TGF-beta is specified. Smad proteins are critical mediators of TGF-beta signalling. After stimulation by TGF-beta, Smad2 and Smad3 become phosphorylated by the activated TGF-beta receptor kinases, oligomerize with Smad4, translocate to the nucleus and regulate the expression of TGF-beta target genes. Here we report that the sensitivity to TGF-beta induced apoptosis is regulated by crosstalk between the Akt/PKB serine/threonine kinase and Smad3 through a mechanism that is independent of Akt kinase activity. Akt interacts directly with unphosphorylated Smad3 to sequester it outside the nucleus, preventing its phosphorylation and nuclear translocation. This results in inhibition of Smad3-mediated transcription and apoptosis. Furthermore, the ratio of Smad3 to Akt correlates with the sensitivity of cells to TGF-beta induced apoptosis. Alteration of this ratio changes the apoptotic, but not the growth-inhibitory, responses of cells to TGF-beta. These findings identify an important determinant of sensitivity to TGF-beta-induced apoptosis that involves crosstalk between the TGF-beta and phosphatidylinositol-3-OH kinase (PI(3)K) pathways.

Capping Parallel β-Sheets of Acetyl(Ala)6NH2 with an Acetyl(Ala)5ProNH2 Can Arrest the Growth of the Sheet, Suggesting a Potential for Curtailing Amyloid Growth. An ONIOM and Density Functional Theory Study

PubMed Central

2015-01-01

We present ONIOM calculations using B3LYP/d95(d,p) as the high level and AM1 as the medium level on parallel β-sheets containing four strands of Ac-AAAAAA-NH2 capped with either Ac-AAPAAA-NH2 or Ac-AAAPAA-NH2. Because Pro can form H-bonds from only one side of the peptide linkage (that containing the C=O H-bond acceptor), only one of the two Pro-containing strands can favorably add to the sheet on each side. Surprisingly, when the sheet is capped with AAPAAA-NH2 at one edge, the interaction between the cap and sheet is slightly more stabilizing than that of another all Ala strand. Breaking down the interaction enthalpies into H-bonding and distortion energies shows the favorable interaction to be due to lower distortion energies in both the strand and the four-stranded sheet. Because another strand would be inhibited for attachment to the other side of the capping (Pro-containing) strand, we suggest the possible use of Pro residues in peptides designed to arrest the growth of many amyloids. PMID:24422496

The antiproliferative cytostatic effects of a self-activating viridin prodrug

PubMed Central

Smith, Adam; Blois, Joseph; Yuan, Hushan; Aikawa, Elena; Ellson, Christian; Figueiredo, Jose-Luiz; Weissleder, Ralph; Kohler, Rainer; Yaffe, Michael B.; Cantley, Lewis C.; Josephson, Lee

2009-01-01

Although viridins like wortmannin (Wm) have long been examined as anticancer agents, their ability to self-activate has only recently been recognized. Here, we describe the cytostatic effects of a self-activating viridin (SAV), which is an inactive, polymeric prodrug. SAV self-activates to generate a bioactive, fluorescent viridin NBD-Wm with a half-time of 9.2 hours. With cultured A549 cells, 10 µmol/L SAV caused growth arrest without inducing apoptosis or cell death, a cytostatic action markedly different from other chemotherapeutic agents (vinblastine, camptothecin, and paclitaxel). In vivo, a SAV dosing of 1 mg/kg once in 48 hours (i.p.) resulted in growth arrest of an A549 tumor xenograft, with growth resuming when dosing ceased. With a peak serum concentration of SAV of 2.36 µmol/L (at 2 hours post i.p. injection), the concentration of bioactive NBD-Wm was 41 nmol/L based on the partial inhibition of neutrophil respiratory burst. Therefore, SAV was present as an inactive prodrug in serum (peak = 2.36 µmol/L), which generated low concentrations of active viridin (41 nmol/L). SAV is a prodrug, the slowrelease and cytostatic activities of which suggest that it might be useful as a component of metronomic-based chemotherapeutic strategies. PMID:19509266

The diacylglycerol acyltransferase Rv3371 of Mycobacterium tuberculosis is required for growth arrest and involved in stress-induced cell wall alterations.

PubMed

Rastogi, Shivangi; Singh, Amit Kumar; Chandra, Gyan; Kushwaha, Pragati; Pant, Garima; Singh, Kavita; Mitra, Kalyan; Sashidhara, Koneni V; Krishnan, Manju Y

2017-05-01

Triacylglycerol (TAG) is important to mycobacteria both as cell envelope component and energy reservoir. Mycobacterium tuberculosis (Mtb) genome encodes at least 15 putative TAG synthase (tgs)s. We report that one of these genes, Rv3371, specific to pathogenic mycobacteria, when expressed in M. smegmatis leads to modifications in colony morphotype, bacterial architecture, cell surface properties and elevated TAG levels. Rv3371 was found to largely localize in the cell membrane. The Rv3371 promoter is minimally active during exponential growth in vitro, however, is up-regulated under stationary phase, hypoxia, nutrient starvation, nitrosative stress, low iron, in IFN-γ activated macrophages and infected mice. The low iron-induced expression of Rv3371 is likely due to the de-repression by Rv1404, which is probably activated by ideR. An Rv3371 deletion mutant of Mtb showed impaired non-replicating persistence in vitro and altered sensitivity to anti-mycobacterial drugs. In low iron medium, the Rv3371 deletion mutant showed reduced formation of TAG containing extracellular vesicles. Therefore Rv3371 is likely involved in Mtb growth arrest and cell wall alterations during persistence. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cold crystalloid versus warm blood cardioplegia in patients undergoing aortic valve replacement.

PubMed

Nardi, Paolo; Vacirca, Sara R; Russo, Marco; Colella, Dionisio F; Bassano, Carlo; Scafuri, Antonio; Pellegrino, Antonio; Melino, Gerry; Ruvolo, Giovanni

2018-03-01

Myocardial protection techniques during cardiac arrest have been extensively investigated in the clinical setting of coronary revascularization. Fewer studies have been carried out of patients affected by left ventricular hypertrophy, where the choice of type and temperature of cardioplegia remain controversial. We have retrospectively investigated myocardial injury and short-term outcome in patients undergoing aortic valve replacement plus or minus coronary artery bypass grafting with using cold crystalloid cardioplegia (CCC) or warm blood cardioplegia (WBC). From January 2015 to October 2016, 191 consecutive patients underwent aortic valve replacement plus or minus coronary artery bypass grafting in normothermic cardiopulmonary bypass. Cardiac arrest was obtained with use of intermittent antegrade CCC group (n=32) or WBC group (n=159), according with the choice of the surgeon. As compared with WBC group, in CCC group creatine-kinase-MB (CK-MB), cardiac troponin I (cTnI), aspartate aminotransferase (AST) release, and their peak levels, were lower during each time points of evaluation, with the greater statistically significant difference at time 0 (P<0.05, for all comparisons). A time 0, CK-MB/CK ratio >10% was 5.9% in CCC group versus 7.8% in WBC group (P<0.0001). At time 0 CK-MB/CK ratio >10% in patients undergoing isolated aortic valve replacement was 6.0% in CCC group versus 8.0% in WBC group (P<0.01). No any difference was found in perioperative myocardial infarction (0% versus 3.8%), postoperative (PO) major complications (15.6% versus 16.4%), in-hospital mortality (3.1% versus 1.3%). In aortic valve surgery a significant decrease of myocardial enzymes release is observed in favor of CCC, but this difference does not translate into different clinical outcome. However, this study suggests that in presence of cardiac surgical conditions associated with significant left ventricular hypertrophy, i.e., the aortic valve disease, a better myocardial protection can be achieved with the use of a cold rather than a warm cardioplegia. Therefore, CCC can be still safely used.

Bcl-2/Bcl-xL inhibition increases the efficacy of MEK inhibition alone and in combination with PI3 kinase inhibition in lung and pancreatic tumor models.

PubMed

Tan, Nguyen; Wong, Maureen; Nannini, Michelle A; Hong, Rebecca; Lee, Leslie B; Price, Stephen; Williams, Karen; Savy, Pierre Pascal; Yue, Peng; Sampath, Deepak; Settleman, Jeffrey; Fairbrother, Wayne J; Belmont, Lisa D

2013-06-01

Although mitogen-activated protein (MAP)-extracellular signal-regulated kinase (ERK) kinase (MEK) inhibition is predicted to cause cell death by stabilization of the proapoptotic BH3-only protein BIM, the induction of apoptosis is often modest. To determine if addition of a Bcl-2 family inhibitor could increase the efficacy of a MEK inhibitor, we evaluated a panel of 53 non-small cell lung cancer and pancreatic cancer cell lines with the combination of navitoclax (ABT-263), a Bcl-2/Bcl-xL (BCL2/BCL2L1) antagonist, and a novel MAP kinase (MEK) inhibitor, G-963. The combination is synergistic in the majority of lines, with an enrichment of cell lines harboring KRAS mutations in the high synergy group. Cells exposed to G-963 arrest in G1 and a small fraction undergo apoptosis. The addition of navitoclax to G-963 does not alter the kinetics of cell-cycle arrest, but greatly increases the percentage of cells that undergo apoptosis. The G-963/navitoclax combination was more effective than either single agent in the KRAS mutant H2122 xenograft model; BIM stabilization and PARP cleavage were observed in tumors, consistent with the mechanism of action observed in cell culture. Addition of the phosphatidylinositol 3-kinase (PI3K, PIK3CA) inhibitor GDC-0941 to this treatment combination increases cell killing compared with double- or single-agent treatment. Taken together, these data suggest the efficacy of agents that target the MAPK and PI3K pathways can be improved by combination with a Bcl-2 family inhibitor. ©2013 AACR

Characteristics and outcomes in patients undergoing percutaneous coronary intervention following cardiac arrest (from the NCDR).

PubMed

Gupta, Navdeep; Kontos, Michael C; Gupta, Aditi; Dai, David; Vetrovec, George W; Roe, Matthew T; Messenger, John

2014-04-01

Outcomes in patients with out-of-hospital cardiac arrest (CA) who undergo percutaneous coronary intervention (PCI) have been limited to small, mostly single-center studies. We compared patients who underwent PCI after CA included in the CathPCI Registry with those without CA. Patients with ST elevation were classified as ST-elevation myocardial infarction (STEMI); all other patients having PCI were classified as without STEMI. Patients with CA in each group were compared with the corresponding non-CA groups for baseline characteristics, angiographic findings, and outcomes. A total of 594,734 patients underwent PCI, of whom 114,768 had STEMI, including 9,375 (8.2%) had CA, and 479,966 had without STEMI, including 2,775 (0.6%) had CA. Patients with CA were similar in age to patients with non-CA, with a lower frequency of coronary disease risk factors and known coronary disease. On angiography, patients with CA were significantly more likely to have more complex lesions with worse baseline thrombolysis in myocardial infarction flow. Patients with CA were significantly more likely to have cardiogenic shock, both for patients with STEMI (51% vs 7.2%, respectively) and for patients without STEMI (38% vs 0.8%, respectively, both p<0.001). In-hospital mortality was substantially worse in patients with CA, for both patients with STEMI (24.9% vs 3.1%, respectively) and patients without STEMI (18.7% vs 0.4%, respectively). In conclusion, patients who underwent PCI after CA had more complex anatomy, more shock, and higher mortality. The substantially increased mortality in patients with CA has important implications for the development and regionalization of centers for CA. Copyright © 2014 Elsevier Inc. All rights reserved.

Lamin B receptor regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: implications for cholesterol biosynthesis in regulating myelopoiesis.

PubMed

Subramanian, Gayathri; Chaudhury, Pulkit; Malu, Krishnakumar; Fowler, Samantha; Manmode, Rahul; Gotur, Deepali; Zwerger, Monika; Ryan, David; Roberti, Rita; Gaines, Peter

2012-01-01

Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin-binding domains plus a C-terminal sterol Δ(14) reductase domain. LBR expression increases during neutrophil differentiation, and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus, LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (erythroid, myeloid, and lymphoid [EML]-derived promyelocytes) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. In this study, we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EML-derived promyelocytes, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full-length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol Δ(14) reductase domain of LBR plays a critical role in cholesterol biosynthesis and that this process is essential to both myeloid cell growth and functional maturation.

Lamin B receptor (LBR) regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: Implications for cholesterol biosynthesis in regulating myelopoiesis

PubMed Central

Subramanian, Gayathri; Chaudhury, Pulkit; Malu, Krishnakumar; Fowler, Samantha; Manmode, Rahul; Gotur, Deepali; Zwerger, Monika; Ryan, David; Roberti, Rita; Gaines, Peter

2011-01-01

Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin binding domains plus a C-terminal sterol Δ14 reductase domain. LBR expression increases during neutrophil differentiation and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (EPRO cells) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. Here we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EPRO cells, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol Δ14 reductase domain of LBR plays a critical role in cholesterol biosynthesis, and that this process is essential to both myeloid cell growth and functional maturation. PMID:22140257

Ovary Apical Abortion under Water Deficit Is Caused by Changes in Sequential Development of Ovaries and in Silk Growth Rate in Maize.

PubMed

Oury, Vincent; Tardieu, François; Turc, Olivier

2016-06-01

Grain abortion allows the production of at least a few viable seeds under water deficit but causes major yield loss. It is maximum for water deficits occurring during flowering in maize (Zea mays). We have tested the hypothesis that abortion is linked to the differential development of ovary cohorts along the ear and to the timing of silk emergence. Ovary volume and silk growth were followed over 25 to 30 d under four levels of water deficit and in four hybrids in two experiments. A position-time model allowed characterizing the development of ovary cohorts and their silk emergence. Silk growth rate decreased in water deficit and stopped 2 to 3 d after first silk emergence, simultaneously for all ovary cohorts, versus 7 to 8 d in well-watered plants. Abortion rate in different treatments and positions on the ear was not associated with ovary growth rate. It was accounted for by the superposition of (1) the sequential emergence of silks originating from ovaries of different cohorts along the ear with (2) one event occurring on a single day, the simultaneous silk growth arrest. Abortion occurred in the youngest ovaries whose silks did not emerge 2 d before silk arrest. This mechanism accounted for more than 90% of drought-related abortion in our experiments. It resembles the control of abortion in a large range of species and inflorescence architectures. This finding has large consequences for breeding drought-tolerant maize and for modeling grain yields in water deficit. © 2016 American Society of Plant Biologists. All Rights Reserved.

Ovary Apical Abortion under Water Deficit Is Caused by Changes in Sequential Development of Ovaries and in Silk Growth Rate in Maize1[OPEN

PubMed Central

Tardieu, François

2016-01-01

Grain abortion allows the production of at least a few viable seeds under water deficit but causes major yield loss. It is maximum for water deficits occurring during flowering in maize (Zea mays). We have tested the hypothesis that abortion is linked to the differential development of ovary cohorts along the ear and to the timing of silk emergence. Ovary volume and silk growth were followed over 25 to 30 d under four levels of water deficit and in four hybrids in two experiments. A position-time model allowed characterizing the development of ovary cohorts and their silk emergence. Silk growth rate decreased in water deficit and stopped 2 to 3 d after first silk emergence, simultaneously for all ovary cohorts, versus 7 to 8 d in well-watered plants. Abortion rate in different treatments and positions on the ear was not associated with ovary growth rate. It was accounted for by the superposition of (1) the sequential emergence of silks originating from ovaries of different cohorts along the ear with (2) one event occurring on a single day, the simultaneous silk growth arrest. Abortion occurred in the youngest ovaries whose silks did not emerge 2 d before silk arrest. This mechanism accounted for more than 90% of drought-related abortion in our experiments. It resembles the control of abortion in a large range of species and inflorescence architectures. This finding has large consequences for breeding drought-tolerant maize and for modeling grain yields in water deficit. PMID:26598464

KPNA7, a nuclear transport receptor, promotes malignant properties of pancreatic cancer cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laurila, Eeva; Vuorinen, Elisa; Fimlab Laboratories, Biokatu 4, 33520 Tampere

2014-03-10

Pancreatic cancer is an aggressive malignancy and one of the leading causes of cancer deaths. The high mortality rate is mostly due to the lack of appropriate tools for early detection of the disease and a shortage of effective therapies. We have previously shown that karyopherin alpha 7 (KPNA7), the newest member of the alpha karyopherin family of nuclear import receptors, is frequently amplified and overexpressed in pancreatic cancer. Here, we report that KPNA7 expression is absent in practically all normal human adult tissues but elevated in several pancreatic cancer cell lines. Inhibition of KPNA7 expression in AsPC-1 and Hs700Tmore » pancreatic cancer cells led to a reduction in cell growth and decreased anchorage independent growth, as well as increased autophagy. The cell growth effects were accompanied by an induction of the cell cycle regulator p21 and a G1 arrest of the cell cycle. Interestingly, the p21 induction was caused by increased mRNA synthesis and not defective nuclear transport. These data strongly demonstrate that KPNA7 silencing inhibits the malignant properties of pancreatic cancer cells in vitro and thereby provide the first evidence on the functional role for KPNA7 in human cancer. - Highlights: • KPNA7 expression is elevated in several pancreatic cancer cell lines. • KPNA7 silencing in high expressing cancer cells leads to growth inhibition. • The cell growth reduction is associated with p21 induction and G1 arrest. • KPNA7 silencing is also accompanied with increased autophagy.« less

Disintegration of microtubules in Arabidopsis thaliana and bladder cancer cells by isothiocyanates

PubMed Central

Øverby, Anders; Bævre, Mette S.; Thangstad, Ole P.; Bones, Atle M.

2015-01-01

Isothiocyanates (ITCs) from biodegradation of glucosinolates comprise a group of electrophiles associated with growth-inhibitory effects in plant- and mammalian cells. The underlying modes of action of this feature are not fully understood. Clarifying this has involved mammalian cancer cells due to ITCs' chemopreventive potential. The binding of ITCs to tubulins has been reported as a mechanism by which ITCs induce cell cycle arrest and apoptosis. In the present study we demonstrate that ITCs disrupt microtubules in Arabidopsis thaliana contributing to the observed inhibited growth phenotype. We also confirmed this in rat bladder cancer cells (AY-27) suggesting that cells from plant and animals share mechanisms by which ITCs affect growth. Exposure of A. thaliana to vapor-phase of allyl ITC (AITC) inhibited growth and induced a concurrent bleaching of leaves in a dose-dependent manner. Transcriptional analysis was used to show an upregulation of heat shock-genes upon AITC-treatment. Transgenic A. thaliana expressing GFP-marked α-tubulin was employed to show a time- and dose-dependent disintegration of microtubules by AITC. Treatment of AY-27 with ITCs resulted in a time- and dose-dependent decrease of cell proliferation and G2/M-arrest. AY-27 transiently transfected to express GFP-tagged α-tubulin were treated with ITCs resulting in a loss of microtubular filaments and the subsequent formation of apoptotic bodies. In conclusion, our data demonstrate an ITC-induced mechanism leading to growth inhibition in A. thaliana and rat bladder cancer cells, and expose clues to the mechanisms underlying the physiological role of glucosinolates in vivo. PMID:25657654

Piper nigrum ethanolic extract rich in piperamides causes ROS overproduction, oxidative damage in DNA leading to cell cycle arrest and apoptosis in cancer cells.

PubMed

de Souza Grinevicius, Valdelúcia Maria Alves; Kviecinski, Maicon Roberto; Santos Mota, Nádia Sandrini Ramos; Ourique, Fabiana; Porfirio Will Castro, Luiza Sheyla Evenni; Andreguetti, Rafaela Rafognato; Gomes Correia, João Francisco; Filho, Danilo Wilhem; Pich, Claus Tröger; Pedrosa, Rozangela Curi

2016-08-02

Ayurvedic and Chinese traditional medicine and tribal people use herbal preparations containing Piper nigrum fruits for the treatment of many health disorders like inflammation, fever, asthma and cancer. In Brazil, traditional maroon culture associates the spice Piper nigrum to health recovery and inflammation attenuation. The aim of the current work was to evaluate the relationship between reactive oxygen species (ROS) overproduction, DNA fragmentation, cell cycle arrest and apoptosis induced by Piper nigrum ethanolic extract and its antitumor activity. The plant was macerated in ethanol. Extract constitution was assessed by TLC, UV-vis and ESI-IT-MS/MS spectrometry. The cytotoxicity, proliferation and intracellular ROS generation was evaluated in MCF-7 cells. DNA damage effects were evaluated through intercalation into CT-DNA, plasmid DNA cleavage and oxidative damage in CT-DNA. Tumor growth inhibition, survival time increase, apoptosis, cell cycle arrest and oxidative stress were assessed in Ehrlich ascites carcinoma-bearing mice. Extraction yielded 64mg/g (36% piperine and 4.2% piperyline). Treatments caused DNA damage and reduced cell viability (EC50=27.1±2.0 and 80.5±6.6µg/ml in MCF-7 and HT-29 cells, respectively), inhibiting cell proliferation by 57% and increased ROS generation in MCF-7 cells (65%). Ehrlich carcinoma was inhibited by the extract, which caused reduction of tumor growth (60%), elevated survival time (76%), cell cycle arrest and induced apoptosis. The treatment with extract increased Bax and p53 and inhibited Bcl-xL and cyclin A expression. It also induced an oxidative stress in vivo verified as enhanced lipid peroxidation and carbonyl proteins content and increased activities of glutathione reductase, superoxide dismutase and catalase. GSH concentration was decreased in tumor tissue from mice. The ethanolic extract has cytotoxic and antiproliferative effect on MCF-7 cells and antitumor effect in vivo probably due to ROS overproduction that induced oxidative stress affecting key proteins involved in cell cycle arrest at G1/S and triggering apoptosis. Finally, the overall data from this study are well in line with the traditional claims for the antitumor effect of Piper nigrum fruits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Role of G-protein-coupled estrogen receptor (GPER/GPR30) in maintenance of meiotic arrest in fish oocytes.

PubMed

Thomas, Peter

2017-03-01

An essential role for GPER (formerly known as GPR30) in regulating mammalian reproduction has not been identified to date, although it has shown to be involved in the regulation a broad range of other estrogen-dependent functions. In contrast, an important reproductive role for GPER in the maintenance of oocyte meiotic arrest has been identified in teleost fishes, which is briefly reviewed here. Recent studies have clearly shown that ovarian follicle production of estradiol-17β (E 2 ) maintains meiotic arrest in several teleost species through activation of GPER coupled to a stimulatory G protein (G s ) on oocyte plasma membranes resulting in stimulation of cAMP production and maintenance of elevated cAMP levels. Studies with denuded zebrafish oocytes and with microinjection of GPER antisense oligonucleotides into oocytes have demonstrated the requirement for both ovarian follicle production of estrogens and expression of GPER on the oocyte surface for maintenance of meiotic arrest. This inhibitory action of E 2 on the resumption of meiosis is mimicked by the GPER-selective agonist G-1, by the GPER agonists and nuclear ER antagonists, ICI 182,780 and tamoxifen, and also by the xenoestrogen bisphenol-A (BPA) and related alkylphenols. GPER also maintains meiotic arrest of zebrafish oocytes through estrogen- and BPA-dependent GPER activation of epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase (MAPK) signaling. Interestingly, progesterone receptor component 1 (PGRMC1) is also involved in estrogen maintenance of meiotic arrest through regulation of EGFR expression on the oocyte plasma membrane. The preovulatory surge in LH secretion induces the ovarian synthesis of progestin hormones that activate a membrane progestin receptor alpha (mPRα)/inhibitory G protein (Gi) pathway. It also increases ovarian synthesis of the catecholestrogen, 2-hydroxy-estradiol-17β (2-OHE 2 ) which inhibits the GPER/Gs/adenylyl cyclase pathway. Both of these LH actions cause declines in oocyte cAMP levels resulting in the resumption of meiosis. GPER is also present on murine oocytes but there are no reports of studies investigating its possible involvement in maintaining meiotic arrest in mammals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reprint of "Role of G protein-coupled estrogen receptor (GPER/GPR30) in maintenance of meiotic arrest in fish oocytes".

PubMed

Thomas, Peter

2018-02-01

An essential role for GPER (formerly known as GPR30) in regulating mammalian reproduction has not been identified to date, although it has shown to be involved in the regulation a broad range of other estrogen-dependent functions. In contrast, an important reproductive role for GPER in the maintenance of oocyte meiotic arrest has been identified in teleost fishes, which is briefly reviewed here. Recent studies have clearly shown that ovarian follicle production of estradiol-17β (E 2 ) maintains meiotic arrest in several teleost species through activation of GPER coupled to a stimulatory G protein (G s ) on oocyte plasma membranes, resulting in stimulation of cAMP production and maintenance of elevated cAMP levels. Studies with denuded zebrafish oocytes and with microinjection of GPER antisense oligonucleotides into oocytes have demonstrated the requirement for both ovarian follicle production of estrogens and expression of GPER on the oocyte surface for maintenance of meiotic arrest. This inhibitory action of E 2 on the resumption of meiosis is mimicked by the GPER-selective agonist G-1, by the GPER agonists and nuclear ER antagonists, ICI 182,780 and tamoxifen, and also by the xenoestrogen bisphenol-A (BPA) and related alkylphenols. GPER also maintains meiotic arrest of zebrafish oocytes through estrogen- and BPA-dependent GPER activation of epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase (MAPK) signaling. Interestingly, progesterone receptor component 1 (PGRMC1) is also involved in estrogen maintenance of meiotic arrest through regulation of EGFR expression on the oocyte plasma membrane. The preovulatory surge in LH secretion induces the ovarian synthesis of progestin hormones that activate a membrane progestin receptor alpha (mPRα)/inhibitory G protein (Gi) pathway. It also increases ovarian synthesis of the catecholestrogen, 2-hydroxy-estradiol-17β (2-OHE 2 ) which inhibits the GPER/Gs/adenylyl cyclase pathway. Both of these LH actions cause declines in oocyte cAMP levels resulting in the resumption of meiosis. GPER is also present on murine oocytes but there are no reports of studies investigating its possible involvement in maintaining meiotic arrest in mammals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aortic arch repair under moderate hypothermic circulatory arrest with or without antegrade cerebral perfusion based on the extent of repair

PubMed Central

Park, Sung Jun; Jeon, Bo Bae; Kim, Hee Jung

2018-01-01

Background For aortic-arch repair, moderate hypothermic circulatory arrest (HCA) have shown favorable outcomes over conventional deep HCA when coupled with antegrade cerebral perfusion (ACP); however, recent studies have shown that ACP may not be essential when circulatory arrest time is less than 30 minutes. This study aims to evaluate the stratified arch repair strategy of moderate HCA with or without ACP based on the extent of procedure. Methods Consecutive 138 patients (63 female; mean age, 60.2±15.7 years) undergoing open arch repair due to acute aortic syndrome (n=69) or chronic aneurysm (n=69) from January 2012 through April 2017 were enrolled in this study. Stratified neuroprotective strategy was employed according to the extent of repair: hemi-arch repair (n=93) was performed under moderated HCA alone and total-arch repair (n=45) under moderate HCA combined with unilateral ACP. Results Median total circulatory arrest and total procedural times were 8.0 minutes [interquartile range (IQR), 6.0–10.0] and 233.0 minutes (IQR, 196.0–290.0 minutes), respectively in the hemi-arch group, and 25.0 minutes (IQR, 12.0–33.0 minutes) and 349.0 minutes (IQR, 276.0–406.0 minutes), respectively in the total-arch group. Early mortality occurred in 2 patients (1.4%) who underwent hemi-arch repair for acute aortic dissection. There was no permanent neurological injury, but 2 cases (1.4%) of temporary neurologic deficit in the hemi-arch group. Other complications included re-exploration for bleeding in 6 (4.3%), postoperative extracorporeal life support in 5 (3.6%) and new-dialysis in 6 (4.3%). Conclusions Stratified cerebral perfusion strategy using moderate hypothermia for aortic-arch surgery based on the extent of arch repair showed satisfactory safety and reasonable efficiency. PMID:29707342

Quantitative EEG Metrics Differ Between Outcome Groups and Change Over the First 72 h in Comatose Cardiac Arrest Patients.

PubMed

Wiley, Sara Leingang; Razavi, Babak; Krishnamohan, Prashanth; Mlynash, Michael; Eyngorn, Irina; Meador, Kimford J; Hirsch, Karen G

2018-02-01

Forty to sixty-six percent of patients resuscitated from cardiac arrest remain comatose, and historic outcome predictors are unreliable. Quantitative spectral analysis of continuous electroencephalography (cEEG) may differ between patients with good and poor outcomes. Consecutive patients with post-cardiac arrest hypoxic-ischemic coma undergoing cEEG were enrolled. Spectral analysis was conducted on artifact-free contiguous 5-min cEEG epochs from each hour. Whole band (1-30 Hz), delta (δ, 1-4 Hz), theta (θ, 4-8 Hz), alpha (α, 8-13 Hz), beta (β, 13-30 Hz), α/δ power ratio, percent suppression, and variability were calculated and correlated with outcome. Graphical patterns of quantitative EEG (qEEG) were described and categorized as correlating with outcome. Clinical outcome was dichotomized, with good neurologic outcome being consciousness recovery. Ten subjects with a mean age = 50 yrs (range = 18-65) were analyzed. There were significant differences in total power (3.50 [3.30-4.06] vs. 0.68 [0.52-1.02], p = 0.01), alpha power (1.39 [0.66-1.79] vs 0.27 [0.17-0.48], p < 0.05), delta power (2.78 [2.21-3.01] vs 0.55 [0.38-0.83], p = 0.01), percent suppression (0.66 [0.02-2.42] vs 73.4 [48.0-97.5], p = 0.01), and multiple measures of variability between good and poor outcome patients (all values median [IQR], good vs. poor). qEEG patterns with high or increasing power or large power variability were associated with good outcome (n = 6). Patterns with consistently low or decreasing power or minimal power variability were associated with poor outcome (n = 4). These preliminary results suggest qEEG metrics correlate with outcome. In some patients, qEEG patterns change over the first three days post-arrest.

SV40-transformed human fibroblasts: evidence for cellular aging in pre-crisis cells.

PubMed

Stein, G H

1985-10-01

Pre-crisis SV40-transformed human diploid fibroblast (HDF) cultures have a finite proliferative lifespan, but they do not enter a viable senescent state at end of lifespan. Little is known about either the mechanism for this finite lifespan in SV40-transformed HDF or its relationship to finite lifespan in normal HDF. Recently we proposed that in normal HDF the phenomena of finite lifespan and arrest in a viable senescent state depend on two separate processes: 1) an age-related decrease in the ability of the cells to recognize or respond to serum and/or other mitogens such that the cells become functionally mitogen-deprived at the end of lifespan; and 2) the ability of the cells to enter a viable, G1-arrested state whenever they experience mitogen deprivation. In this paper, data are presented that suggest that pre-crisis SV40-transformed HDF retain the first process described above, but lack the second process. It is shown that SV40-transformed HDF have a progressively decreasing ability to respond to serum as they age, but they continue to traverse the cell cycle at the end of lifespan. Concomitantly, the rate of cell death increases steadily toward the end of lifespan, thereby causing the total population to cease growing and ultimately to decline. Previous studies have shown that when SV40-transformed HDF are environmentally serum deprived, they likewise exhibit continued cell cycle traverse coupled with increased cell death. Thus, these results support the hypothesis that pre-crisis SV40-transformed HDF still undergo the same aging process as do normal HDF, but they end their lifespan in crisis rather than in the normal G1-arrested senescent state because they have lost their ability to enter a viable, G1-arrested state in response to mitogen deprivation.

Right Ventricular Ejection Fraction Is Incremental to Left Ventricular Ejection Fraction for the Prediction of Future Arrhythmic Events in Patients With Systolic Dysfunction.

PubMed

Mikami, Yoko; Jolly, Umjeet; Heydari, Bobak; Peng, Mingkai; Almehmadi, Fahad; Zahrani, Mohammed; Bokhari, Mahmoud; Stirrat, John; Lydell, Carmen P; Howarth, Andrew G; Yee, Raymond; White, James A

2017-01-01

Left ventricular ejection fraction remains the primary risk stratification tool used in the selection of patients for implantable cardioverter defibrillator therapy. However, this solitary marker fails to identify a substantial portion of patients experiencing sudden cardiac arrest. In this study, we examined the incremental value of considering right ventricular ejection fraction for the prediction of future arrhythmic events in patients with systolic dysfunction using the gold standard of cardiovascular magnetic resonance. Three hundred fourteen consecutive patients with ischemic cardiomyopathy or nonischemic dilated cardiomyopathy undergoing cardiovascular magnetic resonance were followed for the primary outcome of sudden cardiac arrest or appropriate implantable cardioverter defibrillator therapy. Blinded quantification of left ventricular and right ventricular (RV) volumes was performed from standard cine imaging. Quantification of fibrosis from late gadolinium enhancement imaging was incrementally performed. RV dysfunction was defined as right ventricular ejection fraction ≤45%. Among all patients (164 ischemic cardiomyopathy, 150 nonischemic dilated cardiomyopathy), the mean left ventricular ejection fraction was 32±12% (range, 6-54%) with mean right ventricular ejection fraction of 48±15% (range, 7-78%). At a median of 773 days, 49 patients (15.6%) experienced the primary outcome (9 sudden cardiac arrest, 40 appropriate implantable cardioverter defibrillator therapies). RV dysfunction was independently predictive of the primary outcome (hazard ratio=2.98; P=0.002). Among those with a left ventricular ejection fraction >35% (N=121; mean left ventricular ejection fraction, 45±6%), RV dysfunction provided an adjusted hazard ratio of 4.2 (P=0.02). RV dysfunction is a strong, independent predictor of arrhythmic events. Among patients with mild to moderate LV dysfunction, a cohort greatly contributing to global sudden cardiac arrest burden, this marker provides robust discrimination of high- versus low-risk subjects. © 2017 American Heart Association, Inc.

Homozygous/Compound Heterozygous Triadin Mutations Associated With Autosomal-Recessive Long-QT Syndrome and Pediatric Sudden Cardiac Arrest: Elucidation of the Triadin Knockout Syndrome.

PubMed

Altmann, Helene M; Tester, David J; Will, Melissa L; Middha, Sumit; Evans, Jared M; Eckloff, Bruce W; Ackerman, Michael J

2015-06-09

Long-QT syndrome (LQTS) may result in syncope, seizures, or sudden cardiac arrest. Although 16 LQTS-susceptibility genes have been discovered, 20% to 25% of LQTS remains genetically elusive. We performed whole-exome sequencing child-parent trio analysis followed by recessive and sporadic inheritance modeling and disease-network candidate analysis gene ranking to identify a novel underlying genetic mechanism for LQTS. Subsequent mutational analysis of the candidate gene was performed with polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing on a cohort of 33 additional unrelated patients with genetically elusive LQTS. After whole-exome sequencing and variant filtration, a homozygous p.D18fs*13 TRDN-encoded triadin frameshift mutation was discovered in a 10-year-old female patient with LQTS with a QTc of 500 milliseconds who experienced recurrent exertion-induced syncope/cardiac arrest beginning at 1 year of age. Subsequent mutational analysis of TRDN revealed either homozygous or compound heterozygous frameshift mutations in 4 of 33 unrelated cases of LQTS (12%). All 5 TRDN-null patients displayed extensive T-wave inversions in precordial leads V1 through V4, with either persistent or transient QT prolongation and severe disease expression of exercise-induced cardiac arrest in early childhood (≤3 years of age) and required aggressive therapy. The overall yield of TRDN mutations was significantly greater in patients ≤10 years of age (5 of 10, 50%) compared with older patients (0 of 24, 0%; P=0.0009). We identified TRDN as a novel underlying genetic basis for recessively inherited LQTS. All TRDN-null patients had strikingly similar phenotypes. Given the recurrent nature of potential lethal arrhythmias, patients fitting this phenotypic profile should undergo cardiac TRDN genetic testing. © 2015 American Heart Association, Inc.

Emodin Increases Expression of Insulin-Like Growth Factor Binding Protein 1 through Activation of MEK/ERK/AMPKα and Interaction of PPARγ and Sp1 in Lung Cancer.

PubMed

Tang, Qing; Wu, JingJing; Zheng, Fang; Hann, Swei Sunny; Chen, YuQing

2017-01-01

Emodin has anti-neoplastic activities on multiple tumors. However, the molecular mechanisms underlying this effect still remain to be fully understood. Cell viability and cell cycle distribution were measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays and flow cytometry, respectively. Cell invasion and migration were examined by transwell invasion and wound healing assays. Western blot analysis was performed to examine the phosphorylation and protein expression of AMP-activated protein kinase alpha (AMPKα), extracellular signaling-regulated kinase 1/2 (ERK1/2), peroxisome proliferators-activated receptor gamma (PPARγ), insulin-like growth factor (IGF) binding protein 1 (IGFBP1) and the transcription factor Sp1. QRT-PCR was used to examine the mRNA levels of the IGFBP1 gene. Small interfering RNAs (siRNAs) were used to knockdown PPARγ and IGFBP1 genes. Exogenously expression of IGFBP1 and Sp1 was determined by transient transfection assays. IGFBP1 promoter activity was measured by Secrete-Pair Dual Luminescence Assay Kit. In vivo nude mice xenograft model and bioluminescent imaging system were used to confirm the findings. We showed that emodin induced cell cycle arrest of NSCLC cells. Emodin increased PPARγ protein and luciferase reporter activity, which were abolished by inhibitors of MAPK extracellular signaling-regulated kinase (ERK) kinase (MEK)/ERK and AMPK. Silencing of PPARγ abrogated emodin-inhibited cell growth and cell cycle arrest. Furthermore, emodin elevated IGFBP1 mRNA, protein, and promoter activity through activation of PPARγ. Intriguingly, overexpressed Sp1 attenuated emodin-induced IGFBP1 expression, which was not observed in cells with silenced PPARγ gene. Moreover, silencing of IGFBP1 gene blunted emodin-induced inhibition of cell growth and cell cycle arrest. On the contrary, overexpressed IGFBP1 enhanced emodin-induced phosphorylation of AMPKα and ERK1/2, and restored emodin-inhibited growth in cells with silenced endogenous IGFBP1 gene. Emodin also inhibited growth of lung xenograft tumors and Sp1, and increased IGFBP1 and PPARγ protein expressions In vivo. Collectively, our results show that emodin inhibits growth of non-small-cell lung cancer (NSCLC) cells through ERK and AMPKα-mediated induction of PPARγ, followed by reduction of Sp1. This in turn induces IGFBP1 gene expression. Thus, the signaling cascades, positive feedback loop and cooperative interplay between transcription factors-induced the expression of IGFBP1 gene contribute to the overall responses of emodin. This study provides a novel mechanism by which emodin inhibits growth of human lung cancer cells. © 2017 The Author(s) Published by S. Karger AG, Basel.

Sulforaphane plays common and different roles in tumorigenic and nontumorigenic colon cell growth

USDA-ARS?s Scientific Manuscript database

Sulforaphane (SFN) is a naturally occurring member of the isothiocyanate family of chemopreventive agents and the induction of cell cycle arrest and apoptosis is a key mechanism by which SFN exerts its colon cancer prevention. However, little is known about the differential effects of SFN on colon c...

HTLV-1 Tax Effects on Cellular Mitotic Regulation

DTIC Science & Technology

2007-04-12

39 2 MutagenesisTax mutagenesis and selection for tax mutants...43 Isolation of tax mutants that do not cause growth arrest in S. cerevisiae. .......... 43 Tax mutants selected in W303a are functional in...114). One currently-approved therapeutic agent , Indinavir, is an effective inhibitor of both proteases. New protease inhibitors are currently being

High-polyphenol sorghum bran extract inhibits cancer cell growth through DNA damage, cell cycle arrest, and apoptosis

USDA-ARS?s Scientific Manuscript database

As diet is one of the major controllable factors in cancer development, potentially chemopreventive foods are of significant interest to public health. One such food is sorghum (Sorghum bicolor), a cereal grain that contains varying concentrations of polyphenols. In a panel of 15 sorghum germplasm...

Conserved sequence-specific lincRNA-steroid receptor interactions drive transcriptional repression and direct cell fate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudson, William H.; Pickard, Mark R.; de Vera, Ian Mitchelle S.

2014-12-23

The majority of the eukaryotic genome is transcribed, generating a significant number of long intergenic noncoding RNAs (lincRNAs). Although lincRNAs represent the most poorly understood product of transcription, recent work has shown lincRNAs fulfill important cellular functions. In addition to low sequence conservation, poor understanding of structural mechanisms driving lincRNA biology hinders systematic prediction of their function. Here we report the molecular requirements for the recognition of steroid receptors (SRs) by the lincRNA growth arrest-specific 5 (Gas5), which regulates steroid-mediated transcriptional regulation, growth arrest and apoptosis. We identify the functional Gas5-SR interface and generate point mutations that ablate the SR-Gas5more » lincRNA interaction, altering Gas5-driven apoptosis in cancer cell lines. Further, we find that the Gas5 SR-recognition sequence is conserved among haplorhines, with its evolutionary origin as a splice acceptor site. This study demonstrates that lincRNAs can recognize protein targets in a conserved, sequence-specific manner in order to affect critical cell functions.« less

Small-molecule MDM2 antagonists attenuate the senescence-associated secretory phenotype.

PubMed

Wiley, Christopher D; Schaum, Nicholas; Alimirah, Fatouma; Lopez-Dominguez, Jose Alberto; Orjalo, Arturo V; Scott, Gary; Desprez, Pierre-Yves; Benz, Christopher; Davalos, Albert R; Campisi, Judith

2018-02-05

Processes that have been linked to aging and cancer include an inflammatory milieu driven by senescent cells. Senescent cells lose the ability to divide, essentially irreversibly, and secrete numerous proteases, cytokines and growth factors, termed the senescence-associated secretory phenotype (SASP). Senescent cells that lack p53 tumor suppressor function show an exaggerated SASP, suggesting the SASP is negatively controlled by p53. Here, we show that increased p53 activity caused by small molecule inhibitors of MDM2, which promotes p53 degradation, reduces inflammatory cytokine production by senescent cells. Upon treatment with the MDM2 inhibitors nutlin-3a or MI-63, human cells acquired a senescence-like growth arrest, but the arrest was reversible. Importantly, the inhibitors reduced expression of the signature SASP factors IL-6 and IL-1α by cells made senescent by genotoxic stimuli, and suppressed the ability of senescent fibroblasts to stimulate breast cancer cell aggressiveness. Our findings suggest that MDM2 inhibitors could reduce cancer progression in part by reducing the pro-inflammatory environment created by senescent cells.

Expression of p21Waf1/Cip1 and cyclin D1 is increased in butyrate-resistant HeLa cells.

PubMed

Derjuga, A; Richard, C; Crosato, M; Wright, P S; Chalifour, L; Valdez, J; Barraso, A; Crissman, H A; Nishioka, W; Bradbury, E M; Th'ng, J P

2001-10-12

Sodium butyrate induced cell cycle arrest in mammalian cells through an increase in p21Waf1/Cip1, although another study showed that this arrest is related to pRB signaling. We isolated variants of HeLa cells adapted to growth in 5 mm butyrate. One of these variants, clone 5.1, constitutively expressed elevated levels of p21Waf1/Cip1 when incubated in regular growth medium and in the presence of butyrate. Despite this elevated level of p21Waf1/Cip1, the cells continue to proliferate, albeit at a slower rate than parental HeLa cells. Western blot analyses showed that other cell cycle regulatory proteins were not up-regulated to compensate for the elevated expression of p21Waf1/Cip1. However, cyclin D1 was down-regulated by butyrate in HeLa cells but not in clone 5.1. We conclude that continued expression of cyclin D1 allowed clone 5.1 to grow in the presence of butyrate and elevated levels of p21Waf1/Cip1.

Arrest of cell cycle by inhibition of ribonucleotide reductase induces accumulation of NAD+ by Mn2+-supplemented growth of Corynebacterium ammoniagenes.

PubMed

Abbouni, Bouziane; Elhariry, Hesham M; Auling, Georg

2003-01-01

Cell division of the wild type strain Corynebacterium (formerly Brevibacterium) ammoniagenes ATCC 6872 which requires 1 microM Mn2+ for balanced growth was inhibited by addition of 20 mM hydroxyurea (HU) or 10 mM p-methoxyphenol (MP) to a Mn2+-supplemented fermentation medium at an appropriate time. Scanning electron microscopy (SEM) showed a restricted elongation characteristic of arrest of the cell cycle in coryneform bacteria. The cultures treated with HU or MP had, respectively, a fourfold or sixfold enhanced accumulation of NAD+ by a salvage biosynthetic pathway. An assay of nucleotide-permeable cells for ribonucleotide reductase activity using [3H-CDP] as substrate revealed a pre-early and complete decline of DNA precursor biosynthesis not found in the untreated control. Overproduction of NAD+ is an alternative to the conventional fermentation process using Mn2+ deficiency. A simple model is presented to discuss the metabolic regulation of the new process based on the presence of a manganese ribonucleotide reductase (Mn-RNR) in the producing strain.

Targeting Gas6/TAM in cancer cells and tumor microenvironment.

PubMed

Wu, Guiling; Ma, Zhiqiang; Cheng, Yicheng; Hu, Wei; Deng, Chao; Jiang, Shuai; Li, Tian; Chen, Fulin; Yang, Yang

2018-01-31

Growth arrest-specific 6, also known as Gas6, is a human gene encoding the Gas6 protein, which was originally found to be upregulated in growth-arrested fibroblasts. Gas6 is a member of the vitamin K-dependent family of proteins expressed in many human tissues and regulates several biological processes in cells, including proliferation, survival and migration, by binding to its receptors Tyro3, Axl and Mer (TAM). In recent years, the roles of Gas6/TAM signalling in cancer cells and the tumour microenvironment have been studied, and some progress has made in targeted therapy, providing new potential directions for future investigations of cancer treatment. In this review, we introduce the Gas6 and TAM receptors and describe their involvement in different cancers and discuss the roles of Gas6 in cancer cells, the tumour microenvironment and metastasis. Finally, we introduce recent studies on Gas6/TAM targeting in cancer therapy, which will assist in the experimental design of future analyses and increase the potential use of Gas6 as a therapeutic target for cancer.

Differentiation of NUT Midline Carcinoma by Epigenomic Reprogramming

PubMed Central

Schwartz, Brian E.; Hofer, Matthias D.; Lemieux, Madeleine E.; Bauer, Daniel E.; Cameron, Michael J.; West, Nathan H.; Agoston, Elin S.; Reynoird, Nicolas; Khochbin, Saadi; Ince, Tan A.; Christie, Amanda; Janeway, Katherine A.; Vargas, Sara O.; Perez-Atayde, Antonio R.; Aster, Jon C.; Sallan, Stephen E.; Kung, Andrew L.; Bradner, James E.; French, Christopher A.

2011-01-01

NUT midline carcinoma (NMC) is a lethal pediatric tumor defined by the presence of BRD-NUT fusion proteins that arrest differentiation. Here we explore the mechanisms underlying the ability of BRD4-NUT to prevent squamous differentiation. In both gain-of and loss-of-expression assays we find that expression of BRD4-NUT is associated with globally decreased histone acetylation and transcriptional repression. Bulk chromatin acetylation can be restored by treatment of NMC cells with histone deacetylase inhibitors (HDACi), engaging a program of squamous differentiation and arrested growth in vitro that closely mimics the effects of siRNA mediated attenuation of BRD4-NUT expression. The potential therapeutic utility of HDACi differentiation therapy was established in three different NMC xenograft models, where it produced significant growth inhibition and a survival benefit. Based on these results and translational studies performed with patient-derived primary tumor cells, a child with NMC was treated with the FDA-approved HDAC inhibitor, vorinostat. An objective response was obtained after five weeks of therapy, as determined by positron emission tomography. These findings provide preclinical support for trials of HDACi in patients with NMC. PMID:21447744

All-inside, physeal-sparing anterior cruciate ligament reconstruction does not significantly compromise the physis in skeletally immature athletes: a postoperative physeal magnetic resonance imaging analysis.

PubMed

Nawabi, Danyal H; Jones, Kristofer J; Lurie, Brett; Potter, Hollis G; Green, Daniel W; Cordasco, Frank A

2014-12-01

Anterior cruciate ligament (ACL) reconstruction in skeletally immature patients can result in growth disturbance due to iatrogenic physeal injury. Multiple physeal-sparing ACL reconstruction techniques have been described; however, few combine the benefits of anatomic reconstruction using sockets without violation of the femoral or tibial physis. To utilize physeal-specific magnetic resonance imaging (MRI) to quantify the zone of physeal injury after all-inside ACL reconstruction in skeletally immature athletes. Case series; Level of evidence, 4. Twenty-three skeletally immature patients (mean chronologic age 12.6 years; range, 10-15 years) were prospectively evaluated after all-inside ACL reconstruction. The mean bone age was 13.2 years. There were 8 females and 15 males. Fifteen patients underwent an all-epiphyseal (AE) ACL reconstruction and 8 patients had a partial transphyseal (PTP) ACL reconstruction, which spared the femoral physis but crossed the tibial physis. At 6 and 12 months postoperatively, MRI using 3-dimensional fat-suppressed spoiled gradient recalled echo sequences and full-length standing radiographs were performed to assess graft survival, growth arrest, physeal violation, angular deformity, and leg length discrepancy. The mean follow-up for this cohort was 18.5 months (range, 12-39 months). Minimal tibial physeal violation was seen in 10 of 15 patients in the AE group and, by definition, all patients in the PTP group. The mean area of tibial physeal disturbance (±SD) was 57.8 ± 52.2 mm(2) (mean 2.1% of total physeal area) in the AE group compared with 145.1 ± 100.6 mm(2) (mean 5.4% of total physeal area) in the PTP group (P = .003). Minimal compromise of the femoral physis (1.5%) was observed in 1 case in the PTP group and no cases in the AE group. No cases of growth arrest, articular surface violation, or avascular necrosis were noted on MRI. No postoperative angular deformities or significant leg length discrepancies were observed. The study data suggest that all-inside ACL reconstruction is a safe technique for skeletally immature athletes at short-term follow-up. Physeal-specific MRI reveals minimal growth plate compromise that is significantly lower than published thresholds for growth arrest. © 2014 The Author(s).

[Efficacy of HSV-tk/GCV system on human laryngeal squamous cell cancer in vitro].

PubMed

Ding, Xiu-yong; Qin, Yong; Li, Fu-ying; Cong, Tie-chuan

2006-05-01

Efficacy of HSV-tk/GCV system antitumor effects was assessed on human laryngeal cancer cell line Hep-2 in vitro. To assess the HSV-tk/CGV system whether has an antitumour effect on human laryngeal squamous cell cancer Hep-2 in vitro. The mechanisms of cytotoxity were also assessed. Hep-2 cells were transfected with HSV-tk gene by lipofection. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the HSV-tk gene expression. MTT was utilized to test for the cytotoxicity of this system. The cell-circle arrest and apoptosis were analyzed by flowcytometry assay. HSV-tk gene transfected cells demonstrated obvious cytoreductivity followed by ganciclovir (GCV) administration and this cytoreductivity showed partial GCV dose-independent. HSV-tk gene transfected cells demonstrated obvious s-phase arrest, no apoptosis and necrosis occurred. The HSV-tk/GCV system can inhabit the growth of Hep-2 cells effectively. S-phase arrest perhaps is the main reason that leads to the cell inhibition in our study. HSV-tk/GCV system has potential antitumor effects for the future clinical practice.

Activated stress response pathways within multicellular aggregates utilize an autocrine component.

PubMed

Jack, Graham D; Cabrera, M Carla; Manning, Michael L; Slaughter, Stephen M; Potts, Malcolm; Helm, Richard F

2007-04-01

Multicellular aggregates (spheroids) of primary human foreskin fibroblasts (HFF-2) and a glioblastoma cell line (T98G) entered and exited from long term (2 weeks) metabolic arrest utilizing an autocrine response. Cytokine production (specifically IFN-gamma) activated a Gadd45alpha/p38 pathway that led to increased AP-1 (c-jun and ATF3) transcription factor levels, augmenting cytokine production in an autocrine fashion. Whereas HFF-2 aggregates were capable of surviving long term arrest and recovery during NF-kappaB inhibition independent of JNK activation, T98G aggregates were not. Such endogenous processes are not easily observed with adherent monolayer cell culturing systems, strongly suggesting that more emphasis needs to be placed on determining the operational signal transduction cascades within multicellular aggregates. Extracellular inputs such as spheroid formation, arrest, and regrowth as monolayers invoke intracellular signaling responses converging at the AP-1 transcription factor level. Variations in responses are both cell type and transformation state dependent and require an autocrine cytokine component. The data are discussed in relation to the wounding response and avascular tumor growth mechanisms.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of the Kava Chalcone Flavokawain A Differ in Bladder Cancer Cells with Wild-type versus Mutant p53

PubMed Central

Tang, Yaxiong; Simoneau, Anne R.; Xie, Jun; Shahandeh, Babbak; Zi, Xiaolin

2010-01-01

Flavokawain A is the predominant chalcone from kava extract. We have assessed the mechanisms of flavokawain A's action on cell cycle regulation. In a p53 wild-type, low-grade, and papillary bladder cancer cell line (RT4), flavokawain A increased p21/WAF1 and p27/KIP1, which resulted in a decrease in cyclin-dependent kinase-2 (CDK2) kinase activity and subsequent G1 arrest. The increase of p21/WAF1 protein corresponded to an increased mRNA level, whereas p27/KIP1 accumulation was associated with the down-regulation of SKP2 and then increased the stability of the p27/KIP1 protein. The accumulation of p21/WAF1 and p27/KIP1 was independent of cell cycle position and thus not a result of the cell cycle arrest. In contrast, flavokawain A induced a G2-M arrest in six p53 mutant-type, high-grade bladder cancer cell lines (T24, UMUC3, TCCSUP, 5637, HT1376, and HT1197). Flavokawain A significantly reduced the expression of CDK1-inhibitory kinases, Myt1 and Wee1, and caused cyclin B1 protein accumulation leading to CDK1 activation in T24 cells. Suppression of p53 expression by small interfering RNA in RT4 cells restored Cdc25C expression and down-regulated p21/WAF1 expression, which allowed Cdc25C and CDK1 activation and then led to a G2-M arrest and an enhanced growth-inhibitory effect by flavokawain A. Consistently, flavokawain A also caused a pronounced CDK1 activation and G2-M arrest in p53 knockout but not in p53 wild-type HCT116 cells. This selectivity of flavokawain A for inducing a G2-M arrest in p53-defective cells deserves further investigation as a new mechanism for the prevention and treatment of bladder cancer. PMID:19138991

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

NASA Astrophysics Data System (ADS)

Kim, Joomi

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

Methionine sulfoxide reductase A regulates cell growth through the p53-p21 pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seung Hee; Kim, Hwa-Young, E-mail: hykim@ynu.ac.kr

2011-12-09

Highlights: Black-Right-Pointing-Pointer Down-regulation of MsrA inhibits normal cell proliferation. Black-Right-Pointing-Pointer MsrA deficiency leads to an increase in p21 by enhanced p53 acetylation. Black-Right-Pointing-Pointer Down-regulation of MsrA causes cell cycle arrest at the G{sub 2}/M stage. Black-Right-Pointing-Pointer MsrA is a regulator of cell growth that mediates the p53-p21 pathway. -- Abstract: MsrA is an oxidoreductase that catalyzes the stereospecific reduction of methionine-S-sulfoxide to methionine. Although MsrA is well-characterized as an antioxidant and has been implicated in the aging process and cellular senescence, its roles in cell proliferation are poorly understood. Here, we report a critical role of MsrA in normal cellmore » proliferation and describe the regulation mechanism of cell growth by this protein. Down-regulation of MsrA inhibited cell proliferation, but MsrA overexpression did not promote it. MsrA deficiency led to an increase in p21, a major cyclin-dependent kinase inhibitor, thereby causing cell cycle arrest at the G{sub 2}/M stage. While protein levels of p53 were not altered upon MsrA deficiency, its acetylation level was significantly elevated, which subsequently activated p21 transcription. The data suggest that MsrA is a regulator of cell growth that mediates the p53-p21 pathway.« less

Retinoic acid receptor alpha drives cell cycle progression and is associated with increased sensitivity to retinoids in T-cell lymphoma.

PubMed

Wang, Xueju; Dasari, Surendra; Nowakowski, Grzegorz S; Lazaridis, Konstantinos N; Wieben, Eric D; Kadin, Marshall E; Feldman, Andrew L; Boddicker, Rebecca L

2017-04-18

Peripheral T-cell lymphomas (PTCLs) are aggressive non-Hodgkin lymphomas with generally poor outcomes following standard therapy. Few candidate therapeutic targets have been identified to date. Retinoic acid receptor alpha (RARA) is a transcription factor that modulates cell growth and differentiation in response to retinoids. While retinoids have been used to treat some cutaneous T-cell lymphomas (CTCLs), their mechanism of action and the role of RARA in CTCL and other mature T-cell lymphomas remain poorly understood. After identifying a PTCL with a RARAR394Q mutation, we sought to characterize the role of RARA in T-cell lymphoma cells. Overexpressing wild-type RARA or RARAR394Q significantly increased cell growth in RARAlow cell lines, while RARA knockdown induced G1 arrest and decreased expression of cyclin-dependent kinases CDK2/4/6 in RARAhigh cells. The retinoids, AM80 (tamibarotene) and all-trans retinoic acid, caused dose-dependent growth inhibition, G1 arrest, and CDK2/4/6 down-regulation. Genes down-regulated in transcriptome data were enriched for cell cycle and G1-S transition. Finally, RARA overexpression augmented chemosensitivity to retinoids. In conclusion, RARA drives cyclin-dependent kinase expression, G1-S transition, and cell growth in T-cell lymphoma. Synthetic retinoids inhibit these functions in a dose-dependent fashion and are most effective in cells with high RARA expression, indicating RARA may represent a therapeutic target in some PTCLs.

Transcriptional and post-transcriptional upregulation of p27 mediates growth inhibition of isorhapontigenin (ISO) on human bladder cancer cells.

PubMed

Jiang, Guosong; Huang, Chao; Li, Jingxia; Huang, Haishan; Wang, Jingjing; Li, Yawei; Xie, Fei; Jin, Honglei; Zhu, Junlan; Huang, Chuanshu

2018-03-08

There are few approved drugs available for the treatment of muscle-invasive bladder cancer (MIBC). Recently, we have demonstrated that isorhapontigenin (ISO), a new derivative isolated from the Chinese herb Gnetum cleistostachyum, effectively induces cell-cycle arrest at the G0/G1 phase and inhibits anchorage-independent cell growth through the miR-137/Sp1/cyclin D1 axis in human MIBC cells. Herein, we found that treatment of bladder cancer (BC) cells with ISO resulted in a significant upregulation of p27, which was also observed in ISO-treated mouse BCs that were induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Importantly, knockdown of p27 caused a decline in the ISO-induced G0-G1 growth arrest and reversed ISO suppression of anchorage-independent growth in BC cells. Mechanistic studies revealed that ISO promoted p27 expression at mRNA transcription level through increasing direct binding of forkhead box class O1 (FOXO1) to its promoter, while knockdown of FOXO1 attenuated ISO inhibition of BC cell growth. On the other hand, ISO upregulated the 3'-untranslated region (3'-UTR) activity of p27, which was accompanied by a reduction of miR-182 expression. In line with these observations, ectopic expression of miR-182 significantly blocked p27 3'-UTR activity, whereas mutation of the miR-182-binding site at p27 mRNA 3'-UTR effectively reversed this inhibition. Accordingly, ectopic expression of miR-182 also attenuated ISO upregulation of p27 expression and impaired ISO inhibition of BC cell growth. Our results not only provide novel insight into understanding of the underlying mechanism related to regulation of MIBC cell growth but also identify new roles and mechanisms underlying ISO inhibition of BC cell growth.

Vertebral growth modulation by hemicircumferential electrocoagulation: an experimental study in pigs.

PubMed

Caballero, Alberto; Barrios, Carlos; Burgos, Jesús; Hevia, Eduardo; Correa, Carlos

2011-08-01

This experimental study in pigs was aimed at evaluating spinal growth disorders after partial arrest of the vertebral epiphyseal plates (EP) and neurocentral cartilages (NCC). Unilateral and multisegmental single or combined lesions of the physeal structures were performed by electrocoagulation throughout a video-assisted thoracoscopical approach. Thirty 4-week-old domestic pigs (mean weight 16 kg) were included in the experiments. The superior and inferior epiphyseal plates of T5 to T9 vertebra were damaged in ten animals by hemicircumferential electrocoagulation (group I). In other ten pigs (group II), right NCC at the same T5-T9 levels were damaged. Ten other animals underwent combined lesions of the ipsilateral hemiepiphyseal plates and NCC at the T5-T9 levels. A total of 26 animals could be evaluated after 12 weeks of follow-up using conventional X-rays, CT scans and histology. The pigs with hemicircumferential EP damage developed very slight concave non-structured scoliotic deformities without vertebral rotation.(mean 12° Cobb; range10-16°). Some of the damaged vertebra showed a marked wedgening with unilateral development alteration of the vertebral body, including the adjacent discs The animals with damage of the NCC developed mild scoliotic curves (mean 19° Cobb; range 16-24°) with convexity opposite to the damaged side and loss of physiological kyphosis. The injured segments showed an asymmetric growth with hypoplasia of the pedicle and costovertebral joints at the damaged side. The pigs undergoing combined EP and NCC lesions developed minimal non-structured curves, ranging from 10 to 12° Cobb. In these animals there was a lack of growth of a vertebral hemibody and disc hypoplasia at the damaged segments. Both damage of the NCC and the EP affect the height of the vertebral body. No spinal stenosis was found in any case. In most cases, the adjacent superior and inferior vertebral EP to damaged segments had a compensatory growth that maintained the straight spinal shape. In summary, unilateral direct lesion of the EP by hemicircumferential thoracoscopic electrocoagulation modifies vertebral growth, but is not able to induce true scoliostic curves in pigs. Only animals with damaged NCC developed mild scoliotic curves of lordotic type. This work rediscovers and emphasizes the decisive role of the neurocentral cartilage in the ethiopatogeny of idiopathic scoliosis.

The anti-tumor effect and mechanisms of action of penta-acetyl geniposide.

PubMed

Peng, C H; Huang, C N; Wang, C J

2005-06-01

Gardenia, the fruit of Gardenia jasminoides Ellis, has been widely used to treat liver and gall bladder disorders in Chinese medicine. It has been shown recently that geniposide, the main ingredient of Gardenia Fructus, exhibits the anti-tumor effect. In this review, we discuss the anti-tumor effect and possible mechanisms of a derivative from Gardenia Fructus, penta-acetyl geniposide ((Ac)5GP). It has been demonstrated that (Ac)5GP plays more potent roles than geniposide in chemoprevention. (Ac)5GP decreased DNA damage and hepatocarcinogenesis induced by aflatoxin B1 (AFB1) by activating the phase II enzymes glutathione S-transferase (GST) and GSH peroxidase (GSH-Px). It reduced the growth and development of inoculated C6 glioma cells especially in pre-treated rats. In addition to the preventive effect, (Ac)5GP exerts its actions on apoptosis and growth arrest. Treatment of (Ac)5GP caused DNA fragmentation of glioma cells. (Ac)5GP induced sub- G1 peak through the activation of apoptotic cascades PKCdelta/JNK/Fas/caspase8 and caspase 3. Besides, p53/Bax signaling was suggested to be involved in (Ac)5GP-induced apoptosis, though its downstream cascades needs further clarified. (Ac)5GP has also been shown to inhibit DNA synthesis of tumor cells. It arrested cell cycle at G0/ G1 by inducing the expression of p21, thus suppressing the cyclin D1/cdk4 complex formation and the phosphorylation of E2F. The phosphorylation status of p53 on serine 392 correlated with the process of growth arrest. Evidences from the in vivo experiments showed that (Ac)5GP is not harmful to liver, heart and kidney. In conclusion, (Ac)5GP is highly suggested to be an anti-tumor agent for development in the future.

Geraniol and beta-ionone inhibit proliferation, cell cycle progression, and cyclin-dependent kinase 2 activity in MCF-7 breast cancer cells independent of effects on HMG-CoA reductase activity.

PubMed

Duncan, Robin E; Lau, Dominic; El-Sohemy, Ahmed; Archer, Michael C

2004-11-01

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase catalyzes the formation of mevalonate, a precursor of cholesterol that is also required for cell proliferation. Mevalonate depletion results in a G1 phase cell cycle arrest that is mediated in part by impaired activity of cyclin-dependent kinase (CDK) 2, and decreased expression of positive regulators of G1 to S phase progression. Inhibition of mevalonate synthesis may, therefore, be a useful strategy to impair the growth of malignant cells. Plant isoprenoids, including beta-ionone and geraniol, have previously been shown to inhibit rodent mammary tumor development, and rodent and avian hepatic HMG-CoA reductase activity. We hypothesized that the putative anti-proliferative and cell cycle inhibitory effects of beta-ionone and geraniol on MCF-7 human breast cancer cells in culture are mediated by mevalonate depletion resulting from inhibition of HMG-CoA reductase activity. Flow cytometric analysis showed a G1 arrest in isoprenoid-treated MCF-7 cells, and also a G2/M arrest at higher concentrations of isoprenoids. These compounds minimally affected the growth of MCF-10F normal breast epithelial cells. Both beta-ionone and geraniol inhibited CDK 2 activity and dose-dependently decreased the expression of cyclins D1, E, and A, and CDK 2 and 4, without changing the expression of p21cip1 or p27kip1. Although both beta-ionone and geraniol also inhibited MCF-7 proliferation, only geraniol inhibited HMG-CoA reductase activity. While these effects were significantly correlated (r2=0.89, P <0.01), they were not causally related, since exogenous mevalonate did not restore growth in geraniol-inhibited cells. These findings indicate that mechanisms other than impaired mevalonate synthesis mediate the anti-proliferative and cell cycle regulatory effects of beta-ionone and geraniol in human breast cancer cells.

The therapeutic effects of docosahexaenoic acid on oestrogen/androgen-induced benign prostatic hyperplasia in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chao; Luo, Fei; Zhou, Ying

Benign prostatic hyperplasia (BPH) is one of the major disorders of the urinary system in elderly men. Docosahexaenoic acid (DHA) is the main component of n-3 polyunsaturated fatty acids (n-3 PUFAs) and has nerve protective, anti-inflammatory and tumour-growth inhibitory effects. Here, the therapeutic potential of DHA in treating BPH was investigated. Seal oil effectively prevented the development of prostatic hyperplasia induced by oestradiol/testosterone in a rat model by suppressing the increase of the prostatic index (PI), reducing the thickness of the peri-glandular smooth muscle layer, inhibiting the proliferation of both prostate epithelial and stromal cells, and downregulating the expression ofmore » androgen receptor (AR) and oestrogen receptor α (ERα). An in vitro study showed that DHA inhibited the growth of the human prostate stromal cell line WPMY-1 and the epithelial cell line RWPE-1 in a dose- and time-dependent manner. In both cell lines, the DHA arrested the cell cycle in the G2/M phase. In addition, DHA also reduced the expression of ERα and AR in the WPMY-1 and RWPE-1 cells. These results indicate that DHA inhibits the multiplication of prostate stromal and epithelial cells through a mechanism that may involve cell cycle arrest and the downregulation of ERα and AR expression. - Highlights: • Seal oil prevents oestradiol/testosterone (E2/T)-induced BPH in castrated rats. • Seal oil downregulates the expression of oestrogen receptor α(ERα) and androgen receptor (AR) in rat BPH tissues. • DHA inhibits the growth of human prostate stromal and epithelial cells in vitro. • DHA arrests human prostate stromal and epithelial cells in the G2/M phase and downregulates the expression of cyclin B1. • DHA inhibits the expression of ERα and AR in human prostate stromal and epithelial cells.« less

Solution structure and biophysical characterization of the multifaceted signalling effector protein growth arrest specific-1.

PubMed

Rosti, Katja; Goldman, Adrian; Kajander, Tommi

2015-02-28

The protein growth arrest specific-1 (GAS1) was discovered based on its ability to stop the cell cycle. During development it is involved in embryonic patterning, inhibits cell proliferation and mediates cell death, and has therefore been considered as a tumor suppressor. GAS1 is known to signal through two different cell membrane receptors: Rearranged during transformation (RET), and the sonic hedgehog receptor Patched-1. Sonic Hedgehog signalling is important in stem cell renewal and RET mediated signalling in neuronal survival. Disorders in both sonic hedgehog and RET signalling are connected to cancer progression. The neuroprotective effect of RET is controlled by glial cell-derived neurotrophic factor family ligands and glial cell-derived neurotrophic factor receptor alphas (GFRαs). Human Growth arrest specific-1 is a distant homolog of the GFRαs. We have produced and purified recombinant human GAS1 protein, and confirmed that GAS1 is a monomer in solution by static light scattering and small angle X-ray scattering analysis. The low resolution solution structure reveals that GAS1 is more elongated and flexible than the GFRαs, and the homology modelling of the individual domains show that they differ from GFRαs by lacking the amino acids for neurotrophic factor binding. In addition, GAS1 has an extended loop in the N-terminal domain that is conserved in vertebrates after the divergence of fishes and amphibians. We conclude that GAS1 most likely differs from GFRαs functionally, based on comparative structural analysis, while it is able to bind the extracellular part of RET in a neurotrophic factor independent manner, although with low affinity in solution. Our structural characterization indicates that GAS1 differs from GFRα's significantly also in its conformation, which probably reflects the functional differences between GAS1 and the GFRαs.

Adrenomedullin promotes lung angiogenesis, alveolar development, and repair.

PubMed

Vadivel, Arul; Abozaid, Sameh; van Haaften, Tim; Sawicka, Monika; Eaton, Farah; Chen, Ming; Thébaud, Bernard

2010-08-01

Bronchopulmonary dysplasia (BPD) and emphysema are significant global health problems at the extreme stages of life. Both are characterized by alveolar simplification and abnormal distal airspace enlargement due to arrested development or loss of alveoli, respectively. Both lack effective treatments. Mechanisms that inhibit distal lung growth are poorly understood. Adrenomedullin (AM), a recently discovered potent vasodilator, promotes angiogenesis and has protective effects on the cardiovascular and respiratory system. Its role in the developing lung is unknown. We hypothesized that AM promotes lung angiogenesis and alveolar development. Accordingly, we report that lung mRNA expression of AM increases during normal alveolar development. In vivo, intranasal administration of the AM antagonist, AM22-52 decreases lung capillary density (12.4 +/- 1.5 versus 18 +/- 1.5 in control animals; P < 0.05) and impairs alveolar development (mean linear intercept, 52.3 +/- 1.5 versus 43.8 +/- 1.8 [P < 0.05] and septal counts 62.0 +/- 2.7 versus 90.4 +/- 3.5 [P < 0.05]) in neonatal rats, resulting in larger and fewer alveoli, reminiscent of BPD. This was associated with decreased lung endothelial nitric oxide synthase and vascular endothelial growth factor-A mRNA expression. In experimental oxygen-induced BPD, a model of arrested lung vascular and alveolar growth, AM attenuates arrested lung angiogenesis (vessel density, 6.9 +/- 1.1 versus 16.2 +/- 1.3, P < 0.05) and alveolar development (mean linear intercept, 51.9 +/- 3.2 versus 44.4 +/- 0.7, septal counts 47.6 +/- 3.4 versus 67.7 +/- 4.0, P < 0.05), an effect in part mediated by inhibition of apoptosis. AM also prevents pulmonary hypertension in this model, as assessed by decreased right ventricular hypertrophy and pulmonary artery medial wall thickness. Our findings suggest a role for AM during normal alveolar development. AM may have therapeutic potential in diseases associated with alveolar injury.

Pituitary gigantism causing diabetic ketoacidosis.

PubMed

Alvi, N S; Kirk, J M

1999-01-01

Although growth hormone excess (acromegaly) in association with glucose intolerance and diabetes mellitus is well documented in adult medicine, it is much less common in the paediatric age group. We report the case of a 13 year-old boy who presented with tall stature secondary to a large growth hormone secreting adenoma of the pituitary gland. Random growth hormone was 630 mIU/l and did not suppress during an oral glucose tolerance test. Following debulking of the tumour, he developed diabetic ketoacidosis requiring insulin treatment, but after further surgery glucose handling returned to normal. He has been started on testosterone to arrest further increase in height.

Pathophysiology of ocular surface squamous neoplasia

PubMed Central

Gichuhi, Stephen; Ohnuma, Shin-ichi; Sagoo, Mandeep S.; Burton, Matthew J.

2014-01-01

The incidence of ocular surface squamous neoplasia (OSSN) is strongly associated with solar ultraviolet (UV) radiation, HIV and human papilloma virus (HPV). Africa has the highest incidence rates in the world. Most lesions occur at the limbus within the interpalpebral fissure particularly the nasal sector. The nasal limbus receives the highest intensity of sunlight. Limbal epithelial crypts are concentrated nasally and contain niches of limbal epithelial stem cells in the basal layer. It is possible that these are the progenitor cells in OSSN. OSSN arises in the basal epithelial cells spreading towards the surface which resembles the movement of corneo-limbal stem cell progeny before it later invades through the basement membrane below. UV radiation damages DNA producing pyrimidine dimers in the DNA chain. Specific CC → TT base pair dimer transformations of the p53 tumour-suppressor gene occur in OSSN allowing cells with damaged DNA past the G1-S cell cycle checkpoint. UV radiation also causes local and systemic photoimmunosuppression and reactivates latent viruses such as HPV. The E7 proteins of HPV promote proliferation of infected epithelial cells via the retinoblastoma gene while E6 proteins prevent the p53 tumour suppressor gene from effecting cell-cycle arrest of DNA-damaged and infected cells. Immunosuppression from UV radiation, HIV and vitamin A deficiency impairs tumour immune surveillance allowing survival of aberrant cells. Tumour growth and metastases are enhanced by; telomerase reactivation which increases the number of cell divisions a cell can undergo; vascular endothelial growth factor for angiogenesis and matrix metalloproteinases (MMPs) that destroy the intercellular matrix between cells. Despite these potential triggers, the disease is usually unilateral. It is unclear how HPV reaches the conjunctiva. PMID:25447808

Stress-induced premature senescence (SIPS)--influence of SIPS on radiotherapy.

PubMed

Suzuki, Masatoshi; Boothman, David A

2008-03-01

Replicative senescence is a fundamental feature in normal human diploid cells and results from dysfunctional telomeres at the Hayflick cell division limit. Ionizing radiation (IR) prematurely induces the same phenotypes as replicative senescence prior to the Hayflick limit. This process is known as stress-induced premature senescence (SIPS). Since the cell cycle is irreversibly arrested in SIPS-induced cells, even if they are stimulated by various growth factors, it is thought that SIPS is a form of cell death, irreversibly eliminating replicating cells. IR-induced-focus formation of DNA repair proteins, a marker of DNA damage, is detected in SIPS as well as replicative senescent cells. Furthermore, both processes persistently induce cell cycle checkpoint mechanisms, indicating DNA damage created by ionizing radiation induces SIPS in normal cells, possibly by the same mechanisms as those occurring in replicative senescence. Interestingly, IR induces SIPS not only in normal cells, but also in tumor cells. Due to the expression of telomerase in tumor cells, telomere-dependent replicative senescence does not occur. However, SIPS is induced under certain conditions after IR exposure. Thus, cell death triggered by IR can be attributed to apoptosis or SIPS in tumor cells. However, metabolic function remains intact in SIPS-induced cancer cells, and recent studies show that senescence eliminate cells undergoing SIPS secrete various kinds of factors outside the cell, changing the microenvironment. Evidence using co-culture systems containing normal senescent stromal cells and epithelial tumor cells show that factors secreted from senescent stroma cells promote the growth of tumor epithelial cells both in vitro and in vivo. Thus, regulation of factors secreted from SIPS-induced stromal cells, as well as tumor cells, may affect radiotherapy.

Development of ovary structures in the last larval and adult stages of psyllids (Insecta, Hemiptera, Sternorrhyncha: Psylloidea).

PubMed

Kot, Marta; Büning, Jürgen; Jankowska, Władysława; Drohojowska, Jowita; Szklarzewicz, Teresa

2016-07-01

The development and organization of the ovaries of ten species from four Psylloidea families (Psyllidae, Triozidae, Aphalaridae and Liviidae) have been investigated. The ovaries of the last larval stage (i.e. fifth instar) of all examined species are filled with numerous clusters of cystocytes which undergo synchronous incomplete mitotic division. Cystocytes of the given cluster are arranged into a rosette with polyfusome in the centre. These clusters are associated with single somatic cells. At the end of the fifth instar, the clusters begin to separate from each other, forming spherical ovarioles which are surrounded by a single layer of somatic cells. In the ovarioles of very young females all cystocytes enter the prophase of meiosis and differentiate shortly thereafter into oocytes and trophocytes (nurse cells). Meanwhile, somatic cells differentiate into cells of the inner epithelial sheath surrounding the trophocytes and into the prefollicular cells that encompass the oocytes. During this final differentiation, the trophocytes lose their cell membranes and become syncytial. Oocytes remain cellular and most of them (termed arrested oocytes) do not grow. In the ovarioles of older females, one oocyte encompassed by its follicle cells starts growing, still connected to the syncytial tropharium by a nutritive cord. After the short phase of previtellogenesis alone, the oocyte enters its vitellogenic the growth phase in the vitellarium. At that time, the second oocyte may enter the vitellarium and start its previtellogenic growth. In the light of the obtained results, the phylogeny of psyllids, as well as phylogenetic relationships between taxa of Hemiptera: Sternorrhyncha are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

18FDG-PET predicts pharmacodynamic response to OSI-906, a dual IGF-1R/IR inhibitor, in preclinical mouse models of lung cancer.

PubMed

McKinley, Eliot T; Bugaj, Joseph E; Zhao, Ping; Guleryuz, Saffet; Mantis, Christine; Gokhale, Prafulla C; Wild, Robert; Manning, H Charles

2011-05-15

To evaluate 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography imaging ((18)FDG-PET) as a predictive, noninvasive, pharmacodynamic (PD) biomarker of response following administration of a small-molecule insulin-like growth factor-1 receptor and insulin receptor (IGF-1R/IR) inhibitor, OSI-906. In vitro uptake studies of (3)H-2-deoxy glucose following OSI-906 exposure were conducted evaluating correlation of dose with inhibition of IGF-1R/IR as well as markers of downstream pathways and glucose metabolism. Similarly, in vivo PD effects were evaluated in human tumor cell line xenografts propagated in athymic nude mice by (18)FDG-PET at 2, 4, and 24 hours following a single treatment of OSI-906 for the correlation of inhibition of receptor targets and downstream markers. Uptake of (3)H-2-deoxy glucose and (18)FDG was significantly diminished following OSI-906 exposure in sensitive tumor cells and subcutaneous xenografts (NCI-H292) but not in an insensitive model lacking IGF-1R expression (NCI-H441). Diminished PD (18)FDG-PET, collected immediately following the initial treatment agreed with inhibition of pIGF-1R/pIR, reduced PI3K (phosphoinositide 3-kinase) and MAPK (mitogen activated protein kinase) pathway activity, and predicted tumor growth arrest as measured by high-resolution ultrasound imaging. (18)FDG-PET seems to serve as a rapid, noninvasive PD marker of IGF-1R/IR inhibition following a single dose of OSI-906 and should be explored clinically as a predictive clinical biomarker in patients undergoing IGF-1R/IR-directed cancer therapy. ©2011 AACR.

The all-trans retinoic acid (atRA)-regulated gene Calmin (Clmn) regulates cell cycle exit and neurite outgrowth in murine neuroblastoma (Neuro2a) cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marzinke, Mark A.; Clagett-Dame, Margaret, E-mail: dame@biochem.wisc.edu; Pharmaceutical Science Division, University of Wisconsin-Madison, Madison, WI 53705-2222

2012-01-01

The vitamin A metabolite all-trans retinoic acid (atRA) functions in nervous system development and regulates cell proliferation and differentiation. Neuroblastoma cells (SH-SY5Y and Neuro2a or N2A) exposed to atRA undergo growth inhibition and neuronal differentiation, both of which are preceded by an increase in Clmn mRNA. Treatment of N2A cells with atRA produces a reduction in phosphohistone 3 immunostaining and BrdU incorporation, both indicators of a reduction in cell proliferation. These effects are nearly eliminated in atRA-treated shClmn knockdown cells. Loss of Clmn in the mouse N2A cell line also results in a significant reduction of atRA-mediated neurite outgrowth, amore » response that can be rescued by reintroduction of the Clmn sequence. In contrast, ectopic overexpression of Clmn produces an increase in the cyclin dependent kinase inhibitor, p21{sup Cip1}, a decrease in cyclin D1 protein and an increase in hypophosphorylated Rb, showing that Clmn participates in G{sub 1}/S arrest. Clmn overexpression alone is sufficient to inhibit N2A cell proliferation, whereas both Clmn and atRA must be present to induce neurite outgrowth. This study shows that the atRA-responsive gene Clmn promotes exit from the cell cycle, a requisite event for neuronal differentiation. -- Highlights: Black-Right-Pointing-Pointer Calmin is a retinoic acid-responsive gene. Black-Right-Pointing-Pointer Calmin promotes cell cycle exit in N2A cells. Black-Right-Pointing-Pointer Calmin overexpression increases p21Cip1 and decreases cyclin D1. Black-Right-Pointing-Pointer Calmin is required for RA-induced growth inhibition and neurite outgrowth.« less

Autologous plasma rich in growth factors in the prevention of severe bleeding after teeth extractions in patients with bleeding disorders: a controlled comparison with fibrin glue

PubMed Central

Cocero, Nadia; Pucci, Fabrizio; Messina, Maria; Pollio, Berardino; Mozzati, Marco; Bergamasco, Laura

2015-01-01

Background Dental extractions in haemophiliacs may cause secondary bleeding, requiring repeated surgical and haematological interventions. As a local haemostatic, fibrin glue has recognised efficacy but, as a plasma-derived product, it carries the risk of viral infections. We, therefore, compared fibrin glue with an autologous haemostatic, plasma rich in growth factors (PRGF), in a controlled trial. Material and methods One hundred and twenty patients with different blood disorders were randomised into two cohorts to undergo dental extraction procedures without hospitalisation. Prior to the extractions, patients underwent systemic haematological treatment. Complications were defined as secondary bleeding after the 7-day follow-up period or protracting after the repair procedure. Results There were 106 extractions (7 retained 3rd molars) in the group managed with fibrin glue: secondary bleeding affected 3/60 patients (5%) on the third day after extraction and necessitated additional surgery and systemic treatment (in one case the procedure had to be repeated on the 7th day). In the PRGF arm there were 98 extractions (23 retained 3rd molars): secondary bleeding affected two patients (3.3%) on the first day after extraction and was arrested with surgery without systemic treatment. Four out of the five secondary bleeds occurred in patients with haemophilia A. Concomitant diabetes or liver disease significantly increased the bleeding risk. Discussion The bleeding rates in the study and control arm prove that PRGF works as well as fibrin glue as a local haemostatic. Further assets are that PRGF has autologous origin, does not require additional systemic treatment in post-extraction repair surgery, is associated with an earlier onset of neo-angiogenesis and, overall, can reduce patients’ distress and costs to the health system. PMID:25369587

The developmental outcomes of P0-mediated ARGONAUTE destabilization in tomato.

PubMed

Hendelman, Anat; Kravchik, Michael; Stav, Ran; Zik, Moriyah; Lugassi, Nitsan; Arazi, Tzahi

2013-01-01

The plant protein ARGONAUTE1 (AGO1) functions in multiple RNA-silencing pathways, including those of microRNAs, key regulators of growth and development. Genetic analysis of ago1 mutants with informative defects has provided valuable insights into AGO1's biological functions. Tomato encodes two AGO1 homologs (SlAGO1s), but mutants have not been described to date. To analyze SlAGO1s' involvement in development, we confirmed that both undergo decay in the presence of the Polerovirus silencing suppressor P0 and produce a transgenic responder line (OP:P0HA) that, upon transactivation, expresses P0 C-terminally fused to a hemagglutinin (HA) tag (P0HA) and destabilizes SlAGO1s at the site of expression. By crossing OP:P0HA with a battery of driver lines, constitutive as well as organ- and stage-specific SlAGO1 downregulation was induced in the F1 progeny. Activated plants exhibited various developmental phenotypes that partially overlapped with those of Arabidopsis ago1 mutants. Plants that constitutively expressed P0HA had reduced SlAGO1 levels and increased accumulation of miRNA targets, indicating compromised SlAGO1-mediated silencing. Consistent with this, they exhibited pleiotropic morphological defects and their growth was arrested post-germination. Transactivation of P0HA in young leaf and floral organ primordia dramatically modified corresponding organ morphology, including the radialization of leaflets, petals and anthers, suggesting that SlAGO1s' activities are required for normal lateral organ development and polarity. Overall, our results suggest that the OP:P0HA responder line can serve as a valuable tool to suppress SlAGO1 silencing pathways in tomato. The suppression of additional SlAGOs by P0HA and its contribution to the observed phenotypes awaits investigation.

Class IA PI3K inhibition inhibits cell growth and proliferation in mantle cell lymphoma.

PubMed

Tabe, Yoko; Jin, Linhua; Konopleva, Marina; Shikami, Masato; Kimura, Shinya; Andreeff, Michael; Raffeld, Mark; Miida, Takashi

2014-01-01

Constitutive activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin signaling pathway preferentially occurs in aggressive blastoid variants of mantle cell lymphoma (MCL) and is implicated in the pathogenesis of this disease. In this study, we investigated the role of PI3K isoforms on proliferation of aggressive MCL cells. The changes in cell viability, cell cycle distribution and apoptosis induction by the PI3K isoform-selective inhibitors were evaluated. The molecular basis underlying the effects of the specific inhibition of PI3K isoforms was investigated by Western blot analysis. Our results demonstrated that a class IA PI3K isoform is most commonly involved in the constitutive activation of Akt in aggressive MCL. Treatment with a p110α isoform-specific inhibitor induced prominent cell cycle arrest followed by apoptosis through complete abolishment of phosphorylated (p)-Akt and its downstream targets. An inhibitor of isoform p110δ induced moderate cell cycle arrest with downregulation of p-Akt and p-S6K. A dual inhibitor of p110α and p110δ GDC-0941 caused more prominent cell growth inhibition compared to selective p110α or p110δ inhibitors. Inhibition of the class IB PI3K isoform p110γ did not cause cell cycle arrest or induce apoptosis in MCL cells. These findings suggest that the therapeutic ablation of class IA PI3K may be a promising strategy for the treatment of refractory, aggressive MCL. Copyright © 2013 S. Karger AG, Basel.

Novel action modality of the diterpenoid anisomelic acid causes depletion of E6 and E7 viral oncoproteins in HPV-transformed cervical carcinoma cells.

PubMed

Paul, Preethy; Rajendran, Senthil Kumar; Peuhu, Emilia; Alshatwi, Ali A; Akbarsha, Mohammad A; Hietanen, Sakari; Eriksson, John E

2014-05-15

Cervical cancer, the second most common malignancy among women, is mainly caused by human papilloma virus (HPV) infection. In HPV-positive cervical cancer cells, the activity of p53 and the induction of p21 are inhibited by the HPV oncoproteins E6 and E7. Therefore, blocking the activity of E6 and E7 would serve as an important therapeutic target in these cancer cells. In this study, anisomelic acid (AA), a natural compound belonging to the same diterpenoid family of bioactive compounds as taxol, was found to deplete the E6 and E7 proteins in HPV-positive cervical cancer cells. Consequently, p53 and the p53-responsive gene, p21, were dramatically induced, leading to G2/M-phase cell cycle arrest. AA-mediated cell cycle arrest and p21 expression were canceled when p53 was down-regulated by p53-shRNA. AA also induced p53-independent intrinsic apoptosis by depletion of the cellular inhibitor of apoptosis protein 2 (cIAP2) whose proteosomal degradation is inhibited by E6. The in ovo chick embryo chorioallantoic membrane (CAM) assay showed that anisomelic acid inhibited the tumor growth of the cervical cancer SiHa cells. AA is revealed to hold a novel action modality based on specific targeting of the HPV oncoproteins, which restores p53-mediated growth arrest and induces apoptosis by terminating E6-mediated cIAP2 stabilization. Copyright © 2014 Elsevier Inc. All rights reserved.

Mechanisms of silver diamine fluoride on arresting caries: a literature review.

PubMed

Zhao, Irene Shuping; Gao, Sherry Shiqian; Hiraishi, Noriko; Burrow, Michael Francis; Duangthip, Duangporn; Mei, May Lei; Lo, Edward Chin-Man; Chu, Chun-Hung

2018-04-01

To review the evidence regarding the mechanisms of silver diamine fluoride (SDF) for arresting caries. A literature search was conducted using the keywords silver diamine fluoride, and its alternative names, in seven databases: PubMed, Embase and Scopus (English); China National Knowledge Infrastructure (Chinese); Bilioteca Virtual em Saude (Portuguese); Biblioteca Virtual en Salud Espana (Spanish); and Ichushi-Web (Japanese). The titles and abstracts were screened. Full texts were retrieved for publications that studied mechanisms of actions of SDF, including its effects on remineralisation of carious lesions and on cariogenic bacteria. A total of 1,123 publications were identified. Twenty-nine articles were included and they investigated the effect of SDF on cariogenic bacteria and dental hard tissues. Eleven studies investigated the antibacterial properties of SDF. They found that SDF was bactericidal to cariogenic bacteria, mainly Streptococcus mutans. It inhibited the growth of cariogenic biofilms on teeth. Twenty studies reported the remineralisation of demineralised enamel or dentine by SDF. They found that mineral loss of demineralised enamel and dentine was reduced after SDF treatment. A highly mineralised surface rich in calcium and phosphate was formed on arrested carious lesions. Four studies examined the effect of SDF on dentine collagen. They found that SDF inhibited collagenases (matrix metalloproteinases and cysteine cathepsins) and protected dentine collagen from destruction. SDF is a bactericidal agent and reduces the growth of cariogenic bacteria. It inhibits demineralisation and promotes the remineralisation of demineralised enamel and dentine. It also hampers degradation of the dentine collagen. © 2017 FDI World Dental Federation.

[6]-Gingerol Induces Cell Cycle Arrest and Cell Death of Mutant p53-expressing Pancreatic Cancer Cells

PubMed Central

Park, Yon Jung; Wen, Jing; Bang, Seungmin; Park, Seung Woo

2006-01-01

[6]-Gingerol, a major phenolic compound derived from ginger, has anti-bacterial, anti-inflammatory and anti-tumor activities. While several molecular mechanisms have been described to underlie its effects on cells in vitro and in vivo, the underlying mechanisms by which [6]-gingerol exerts anti-tumorigenic effects are largely unknown. The purpose of this study was to investigate the action of [6]-gingerol on two human pancreatic cancer cell lines, HPAC expressing wild-type (wt) p53 and BxPC-3 expressing mutated p53. We found that [6]-gingerol inhibited the cell growth through cell cycle arrest at G1 phase in both cell lines. Western blot analyses indicated that [6]-gingerol decreased both Cyclin A and Cyclin-dependent kinase (Cdk) expression. These events led to reduction in Rb phosphorylation followed by blocking of S phase entry. p53 expression was decreased by [6]-gingerol treatment in both cell lines suggesting that the induction of Cyclin-dependent kinase inhibitor, p21cip1, was p53-independent. [6]-Gingerol induced mostly apoptotic death in the mutant p53-expressing cells, while no signs of early apoptosis were detected in wild type p53-expressing cells and this was related to the increased phosphorylation of AKT. These results suggest that [6]-gingerol can circumvent the resistance of mutant p53-expressing cells towards chemotherapy by inducing apoptotic cell death while it exerts cytostatic effect on wild type p53-expressing cells by inducing temporal growth arrest. PMID:17066513

Butyrate-induced apoptotic cascade in colonic carcinoma cells: modulation of the beta-catenin-Tcf pathway and concordance with effects of sulindac and trichostatin A but not curcumin.

PubMed

Bordonaro, M; Mariadason, J M; Aslam, F; Heerdt, B G; Augenlicht, L H

1999-10-01

Short-chain fatty acids play a critical role in colonic homeostasis because they stimulate pathways of growth arrest, differentiation, and apoptosis. These effects have been well characterized in colonic cell lines in vitro. We investigated the role of beta-catenin-Tcf signaling in these responses to butyrate and other well-characterized inducers of apoptosis of colonic epithelial cells. Unlike wild-type APC, which down-regulates Tcf activity, butyrate, as well as sulindac and trichostatin A, all inducers of G0-G1 cell cycle arrest and apoptosis in the SW620 colonic carcinoma cell line, up-regulate Tcf activity. In contrast, structural analogues of butyrate that do not induce cell cycle arrest or apoptosis and curcumin, which stimulates G2-M arrest without inducing apoptosis, do not alter Tcf activity. Similar to the cell cycle arrest and apoptotic cascade induced by butyrate, the up-regulation of Tcf activity is dependent upon the presence of a mitochondrial membrane potential, unlike the APC-induced down-regulation, which is insensitive to collapse of the mitochondrial membrane potential. Moreover, the butyrate-induced increase in Tcf activity, which is reflected in an increase in beta-catenin-Tcf complex formation, is independent of the down-regulation caused by expression of wild-type APC. Thus, butyrate and wild-type APC have different and independent effects on beta-catenin-Tcf signaling. These data are consistent with other reports that suggest that the absence of wild-type APC, associated with the up-regulation of this signaling pathway, is linked to the probability of a colonic epithelial cell entering an apoptotic cascade.

RFX2 Is a Major Transcriptional Regulator of Spermiogenesis

PubMed Central

Kistler, W. Stephen; Baas, Dominique; Lemeille, Sylvain; Paschaki, Marie; Seguin-Estevez, Queralt; Barras, Emmanuèle; Ma, Wenli; Duteyrat, Jean-Luc; Morlé, Laurette

2015-01-01

Spermatogenesis consists broadly of three phases: proliferation of diploid germ cells, meiosis, and finally extensive differentiation of the haploid cells into effective delivery vehicles for the paternal genome. Despite detailed characterization of many haploid developmental steps leading to sperm, only fragmentary information exists on the control of gene expression underlying these processes. Here we report that the RFX2 transcription factor is a master regulator of genes required for the haploid phase. A targeted mutation of Rfx2 was created in mice. Rfx2-/- mice are perfectly viable but show complete male sterility. Spermatogenesis appears to progress unperturbed through meiosis. However, haploid cells undergo a complete arrest in spermatid development just prior to spermatid elongation. Arrested cells show altered Golgi apparatus organization, leading to a deficit in the generation of a spreading acrosomal cap from proacrosomal vesicles. Arrested cells ultimately merge to form giant multinucleated cells released to the epididymis. Spermatids also completely fail to form the flagellar axoneme. RNA-Seq analysis and ChIP-Seq analysis identified 139 genes directly controlled by RFX2 during spermiogenesis. Gene ontology analysis revealed that genes required for cilium function are specifically enriched in down- and upregulated genes showing that RFX2 allows precise temporal expression of ciliary genes. Several genes required for cell adhesion and cytoskeleton remodeling are also downregulated. Comparison of RFX2-regulated genes with those controlled by other major transcriptional regulators of spermiogenesis showed that each controls independent gene sets. Altogether, these observations show that RFX2 plays a major and specific function in spermiogenesis. PMID:26162102

The fatigue response of the aluminium-lithium alloy, 8090

NASA Technical Reports Server (NTRS)

Birt, M. J.; Beevers, C. J.

1989-01-01

The fatigue response of an Al-Li-Cu-Mg-Zr (8090) alloy has been studied at room temperature. The initiation and growth of small and long cracks has been examined at R = 0.1 and at a frequency of 100 Hz. Initiation was observed to occur dominantly at sub-grain boundaries. The growth of the small cracks was crystallographic in character and exhibited little evidence of retardation or arrest at the grain boundaries. The long crack data showed the alloy to have a high resistance to fatigue crack growth with underaging providing the optimum heat treatment for fatigue crack growth resistance. In general, this can be attributed to high levels of crack closure which resulted from the presence of extensive microstructurally related asperities.

Role of TGR-B1-Mediated Down Regulation of NF-kB/Rel Activity During Growth Arrest of Breast Cancer Cells

DTIC Science & Technology

2001-05-01

gallate ( EGCG ), which has been shown to inhibit the induction of NF-KB and growth of breast cancer cell lines in vitro. EGCG reduced NF-KB levels in the...demonstrated activation of NF-KB is induced upon over-expression of Her-2/neu. Thus, studies were initiated with green tea pholyphenol, epigallocatechin -3...NF639 cell line derived from an MMTV-Her-2/neu mouse tumor. NF639 clonal isolates resistant to EGCG appear to display elevated levels of NF-KB. Overall

Disabled-2 Mediation of Retinoic Acid Cell Growth Arrest Signal in Breast Cancer

DTIC Science & Technology

2002-08-01

C. Cohen, L. E. Mendez , I. R. Horowitz, ylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. A. I Godwin, and X X. Xu, submitted for publication. T...trans., 9-cis-retinoic acid) and P- caro - forming units of adenovirus were added to the cells in medium with low tene were purchased from Sigma

[Post-surgical morbidity in paediatric patients undergoing surgery for congenital heart disease in the UMAE of Yucatan, Mexico].

PubMed

Castillo-Espínola, Addy; Velázquez-Ibarra, Ana; Zetina-Solórzano, Aurea; Bolado-García, Patricia; Gamboa-López, Gonzalo

To describe the clinical course of paediatric patients undergoing surgery for congenital heart disease in UMAE of Yucatan. Descriptive review was performed on the records of paediatric patients undergoing surgery for congenital heart disease from 1 November 2011 to 30 November 2013. The most frequent heart diseases were persistent ductus arteriosus (37.6%) and transposition of the great vessels. The median intensive care stay was 3 days. Mortality was 11.76%, with septic shock (44.4%) in most cases. The most frequent complications were sepsis (5.9%), low cardiac output syndrome (4.7%), cardiac arrest, and AV block and ventricular tachycardia (2.4% each). There was a moderate positive correlation between surgical complications and survival or death. The number of surgical patients is lower compared to reference centres for cardiovascular surgery. There is a marked tendency to perform corrective and palliative surgeries in specific disease in patients with added risk or 'bad' cardiac anatomy that prevent full correction at the first attempt. Prospective epidemiological and clinical studies should be conducted to understand the behaviour of congenital heart diseases treated in the region. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Gelation in a model 1-component system with adhesive hard-sphere interactions

NASA Astrophysics Data System (ADS)

Kim, Jung Min; Eberle, Aaron; Fang, Jun; Wagner, Norman

2012-02-01

Colloidal dispersions can undergo a dynamical arrest of the disperse phase leading to a system with solid-like properties when either the volume fraction or the interparticle potential is varied. Systems that contain low to moderate particulate concentrations form gels whereas higher concentrations lead to glassy states in which caging by nearest neighbors can be a significant contributor to the arrested long-time dynamics. Colloid polymer mixtures have been the prevalent model system for studying the effect of attraction, where attractions are entropically driven by depletion effects, in which gelation has been shown to be a result of phase separation [1]. Using the model 1-component octadecyl coated silica nanoparticle system, Eberle et al. [2] found the gel-line to intersect the spinodal to the left of the critical point, and at higher concentrations extended toward the mode coupling theory attractive driven glass line. . We continue this study by varying the particle diameter and find quantitative differences which we explain by gravity. 1. Lu, P.J., et al., Nature, 2008. 453(7194): p. 499-504.2. Eberle, A.P.R., N.J. Wagner, and R. Castaneda-Priego, Physical Review Letters, 2011. 106(10).

Expression Profile of DNA Damage Signaling Genes in Proton Exposed Mouse Brain

NASA Astrophysics Data System (ADS)

Ramesh, Govindarajan; Wu, Honglu

Exposure of living systems to radiation results in a wide assortment of lesions, the most signif-icant of is damage to genomic DNA which induce several cellular functions such as cell cycle arrest, repair, apoptosis etc. The radiation induced DNA damage investigation is one of the im-portant area in biology, but still the information available regarding the effects of proton is very limited. In this report, we investigated the differential gene expression pattern of DNA damage signaling genes particularly, damaged DNA binding, repair, cell cycle arrest, checkpoints and apoptosis using quantitative real-time RT-PCR array in proton exposed mouse brain tissues. The expression profiles showed significant changes in DNA damage related genes in 2Gy proton exposed mouse brain tissues as compared with control brain tissues. Furthermore, we also show that significantly increased levels of apoptotic related genes, caspase-3 and 8 activities in these cells, suggesting that in addition to differential expression of DNA damage genes, the alteration of apoptosis related genes may also contribute to the radiation induced DNA damage followed by programmed cell death. In summary, our findings suggest that proton exposed brain tissue undergo severe DNA damage which in turn destabilize the chromatin stability.

Chemomechanically engineered 3D organotypic platforms of bladder cancer dormancy and reactivation.

PubMed

Pavan Grandhi, Taraka Sai; Potta, Thrimoorthy; Nitiyanandan, Rajeshwar; Deshpande, Indrani; Rege, Kaushal

2017-10-01

Tumors undergo periods of dormancy followed by reactivation leading to metastatic disease. Arrest in the G0/G1 phase of the cell cycle and resistance to chemotherapeutic drugs are key hallmarks of dormant tumor cells. Here, we describe a 3D platform of bladder cancer cell dormancy and reactivation facilitated by a novel aminoglycoside-derived hydrogel, Amikagel. These 3D dormant tumor microenvironments (3D-DTMs) were arrested in the G0/G1 phase and were highly resistant to anti-proliferative drugs. Inhibition of targets in the cellular protein production machinery led to induction of endoplasmic reticulum (ER) stress and complete ablation of 3D-DTMs. Nanoparticle-mediated calcium delivery significantly accelerated ER stress-mediated 3D-DTM death. Transfer of 3D-DTMs onto weaker and adhesive Amikagels resulted in selective reactivation of a sub-population of N-cadherin deficient cells from dormancy. Whole-transcriptome analyses further indicated key biochemical differences between dormant and proliferative cancer cells. Taken together, our results indicate that 3D bladder cancer microenvironments of dormancy and reactivation can facilitate fundamental advances and novel drug discovery in cancer. Copyright © 2017. Published by Elsevier Ltd.

p18(Hamlet) mediates different p53-dependent responses to DNA-damage inducing agents.

PubMed

Lafarga, Vanesa; Cuadrado, Ana; Nebreda, Angel R

2007-10-01

Cells organize appropriate responses to environmental cues by activating specific signaling networks. Two proteins that play key roles in coordinating stress responses are the kinase p38alpha (MAPK14) and the transcription factor p53 (TP53). Depending on the nature and the extent of the stress-induced damage, cells may respond by arresting the cell cycle or by undergoing cell death, and these responses are usually associated with the phosphorylation of particular substrates by p38alpha as well as the activation of specific target genes by p53. We recently characterized a new p38alpha substrate, named p18(Hamlet) (ZNHIT1), which mediates p53-dependent responses to different genotoxic stresses. Thus, cisplatin or UV light induce stabilization of the p18(Hamlet) protein, which then enhances the ability of p53 to bind to and activate the promoters of pro-apoptotic genes such as NOXA and PUMA leading to apoptosis induction. In a similar way, we report here that p18(Hamlet) can also mediate the cell cycle arrest induced in response to gamma-irradiation, by participating in the p53-dependent upregulation of the cell cycle inhibitor p21(Cip1) (CDKN1A).

Efficient immortalization of primary human cells by p16INK4a-specific short hairpin RNA or Bmi-1, combined with introduction of hTERT.

PubMed

Haga, Kei; Ohno, Shin-ichi; Yugawa, Takashi; Narisawa-Saito, Mako; Fujita, Masatoshi; Sakamoto, Michiie; Galloway, Denise A; Kiyono, Tohru

2007-02-01

Activation of telomerase is sufficient for immortalization of some types of human cells but additional factors may also be essential. It has been proposed that stress imposed by inadequate culture conditions induces senescence due to accumulation of p16(INK4a). Here, we present evidence that many human cell types undergo senescence by activation of the p16(INK4a)/Rb pathway, and that introduction of Bmi-1 can inhibit p16(INK4a) expression and extend the life span of human epithelial cells derived from skin, mammary gland and lung. Introduction of p16(INK4a)-specific short hairpin RNA, as well as Bmi-1, suppressed p16(INK4a) expression in human mammary epithelial cells without promoter methylation, and extended their life span. Subsequent introduction of hTERT, the telomerase catalytic subunit, into cells with low p16(INK4a) levels resulted in efficient immortalization of three cell types without crisis or growth arrest. The majority of the human mammary epithelial cells thus immortalized showed almost normal ploidy as judged by G-banding and spectral karyotyping analysis. Our data suggest that inhibition of p16(INK4a) and introduction of hTERT can immortalize many human cell types with little chromosomal instability.

Functional screening in human cardiac organoids reveals a metabolic mechanism for cardiomyocyte cell cycle arrest

PubMed Central

Mills, Richard J.; Titmarsh, Drew M.; Koenig, Xaver; Parker, Benjamin L.; Ryall, James G.; Quaife-Ryan, Gregory A.; Voges, Holly K.; Hodson, Mark P.; Ferguson, Charles; Drowley, Lauren; Plowright, Alleyn T.; Needham, Elise J.; Wang, Qing-Dong; Gregorevic, Paul; Xin, Mei; Thomas, Walter G.; Parton, Robert G.; Nielsen, Lars K.; Elliott, David A.; Porrello, Enzo R.

2017-01-01

The mammalian heart undergoes maturation during postnatal life to meet the increased functional requirements of an adult. However, the key drivers of this process remain poorly defined. We are currently unable to recapitulate postnatal maturation in human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), limiting their potential as a model system to discover regenerative therapeutics. Here, we provide a summary of our studies, where we developed a 96-well device for functional screening in human pluripotent stem cell-derived cardiac organoids (hCOs). Through interrogation of >10,000 organoids, we systematically optimize parameters, including extracellular matrix (ECM), metabolic substrate, and growth factor conditions, that enhance cardiac tissue viability, function, and maturation. Under optimized maturation conditions, functional and molecular characterization revealed that a switch to fatty acid metabolism was a central driver of cardiac maturation. Under these conditions, hPSC-CMs were refractory to mitogenic stimuli, and we found that key proliferation pathways including β-catenin and Yes-associated protein 1 (YAP1) were repressed. This proliferative barrier imposed by fatty acid metabolism in hCOs could be rescued by simultaneous activation of both β-catenin and YAP1 using genetic approaches or a small molecule activating both pathways. These studies highlight that human organoids coupled with higher-throughput screening platforms have the potential to rapidly expand our knowledge of human biology and potentially unlock therapeutic strategies. PMID:28916735

Mechanism of Particle Formation in Silver/Epoxy Nanocomposites Obtained through a Visible-Light-Assisted in Situ Synthesis.

PubMed

dell'Erba, Ignacio E; Martínez, Francisco D; Hoppe, Cristina E; Eliçabe, Guillermo E; Ceolín, Marcelo; Zucchi, Ileana A; Schroeder, Walter F

2017-10-03

A detailed understanding of the processes taking place during the in situ synthesis of metal/polymer nanocomposites is crucial to manipulate the shape and size of nanoparticles (NPs) with a high level of control. In this paper, we report an in-depth time-resolved analysis of the particle formation process in silver/epoxy nanocomposites obtained through a visible-light-assisted in situ synthesis. The selected epoxy monomer was based on diglycidyl ether of bisphenol A, which undergoes relatively slow cationic ring-opening polymerization. This feature allowed us to access a full description of the formation process of silver NPs before this was arrested by the curing of the epoxy matrix. In situ time-resolved small-angle X-ray scattering investigation was carried out to follow the evolution of the number and size of the silver NPs as a function of irradiation time, whereas rheological experiments combined with near-infrared and ultraviolet-visible spectroscopies were performed to interpret how changes in the rheological properties of the matrix affect the nucleation and growth of particles. The analysis of the obtained results allowed us to propose consistent mechanisms for the formation of metal/polymer nanocomposites obtained by light-assisted one-pot synthesis. Finally, the effect of a thermal postcuring treatment of the epoxy matrix on the particle size in the nanocomposite was investigated.

Protein Phosphatase 1ß Limits Ring Canal Constriction during Drosophila Germline Cyst Formation

PubMed Central

Yamamoto, Shinya; Bayat, Vafa; Bellen, Hugo J.; Tan, Change

2013-01-01

Germline cyst formation is essential for the propagation of many organisms including humans and flies. The cytoplasm of germline cyst cells communicate with each other directly via large intercellular bridges called ring canals. Ring canals are often derived from arrested contractile rings during incomplete cytokinesis. However how ring canal formation, maintenance and growth are regulated remains unclear. To better understand this process, we carried out an unbiased genetic screen in Drosophila melanogaster germ cells and identified multiple alleles of flapwing (flw), a conserved serine/threonine-specific protein phosphatase. Flw had previously been reported to be unnecessary for early D. melanogaster oogenesis using a hypomorphic allele. We found that loss of Flw leads to over-constricted nascent ring canals and subsequently tiny mature ring canals, through which cytoplasmic transfer from nurse cells to the oocyte is impaired, resulting in small, non-functional eggs. Flw is expressed in germ cells undergoing incomplete cytokinesis, completely colocalized with the Drosophila myosin binding subunit of myosin phosphatase (DMYPT). This colocalization, together with genetic interaction studies, suggests that Flw functions together with DMYPT to negatively regulate myosin activity during ring canal formation. The identification of two subunits of the tripartite myosin phosphatase as the first two main players required for ring canal constriction indicates that tight regulation of myosin activity is essential for germline cyst formation and reproduction in D. melanogaster and probably other species as well. PMID:23936219

Discovery and characterization of a novel irreversible EGFR mutants selective and potent kinase inhibitor CHMFL-EGFR-26 with a distinct binding mode

PubMed Central

Chen, Cheng; Yu, Kailin; Zou, Fengming; Wang, Wenchao; Wang, Wei; Wu, Jiaxin; Liu, Juan; Wang, Beilei; Wang, Li; Ren, Tao; Zhang, Shanchun; Yun, Cai-Hong; Liu, Jing; Liu, Qingsong

2017-01-01

EGFR T790M mutation accounts for about 40-55% drug resistance for the first generation EGFR kinase inhibitors in the NSCLC. Starting from ibrutinib, a highly potent irreversible BTK kinase inhibitor, which was also found to be moderately active to EGFR T790M mutant, we discovered a highly potent irreversible EGFR inhibitor CHMFL-EGFR-26, which is selectively potent against EGFR mutants including L858R, del19, and L858R/T790M. It displayed proper selectivity window between the EGFR mutants and the wide-type. CHMFL-EGFR-26 exhibited good selectivity profile among 468 kinases/mutants tested (S score (1)=0.02). In addition, X-ray crystallography revealed a distinct “DFG-in” and “cHelix-out” inactive binding mode between CHMFL-EGFR-26 and EGFR T790M protein. The compound showed highly potent anti-proliferative efficacy against EGFR mutant but not wide-type NSCLC cell lines through effective inhibition of the EGFR mediated signaling pathway, induction of apoptosis and arresting of cell cycle progression. CHMFL-EGFR-26 bore acceptable pharmacokinetic properties and demonstrated dose-dependent tumor growth suppression in the H1975 (EGFR L858R/T790M) and PC-9 (EGFR del19) inoculated xenograft mouse models. Currently CHMFL-EGFR-26 is undergoing extensive pre-clinical evaluation for the clinical trial purpose. PMID:28407693

Sul1 and Sul2 Sulfate Transceptors Signal to Protein Kinase A upon Exit of Sulfur Starvation*

PubMed Central

Kankipati, Harish Nag; Rubio-Texeira, Marta; Castermans, Dries; Diallinas, George; Thevelein, Johan M.

2015-01-01

Sulfate is an essential nutrient with pronounced regulatory effects on cellular metabolism and proliferation. Little is known, however, about how sulfate is sensed by cells. Sul1 and Sul2 are sulfate transporters in the yeast Saccharomyces cerevisiae, strongly induced upon sulfur starvation and endocytosed upon the addition of sulfate. We reveal Sul1,2-dependent activation of PKA targets upon sulfate-induced exit from growth arrest after sulfur starvation. We provide two major arguments in favor of Sul1 and Sul2 acting as transceptors for signaling to PKA. First, the sulfate analogue, d-glucosamine 2-sulfate, acted as a non-transported agonist of signaling by Sul1 and Sul2. Second, mutagenesis to Gln of putative H+-binding residues, Glu-427 in Sul1 or Glu-443 in Sul2, abolished transport without affecting signaling. Hence, Sul1,2 can function as pure sulfate sensors. Sul1E427Q and Sul2E443Q are also deficient in sulfate-induced endocytosis, which can therefore be uncoupled from signaling. Overall, our data suggest that transceptors can undergo independent conformational changes, each responsible for triggering different downstream processes. The Sul1 and Sul2 transceptors are the first identified plasma membrane sensors for extracellular sulfate. High affinity transporters induced upon starvation for their substrate may generally act as transceptors during exit from starvation. PMID:25724649

Method for distinguishing normal and transformed cells using G1 kinase inhibitors

DOEpatents

Crissman, Harry A.; Gadbois, Donna M.; Tobey, Robert A.; Bradbury, E. Morton

1993-01-01

A G.sub.1 phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G.sub.1 phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G.sub.1 cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G.sub.1 phase, suggesting that such G.sub.1 phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

Method for distinguishing normal and transformed cells using G1 kinase inhibitors

DOEpatents

Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.

1993-02-09

A G[sub 1] phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G[sub 1] phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G[sub 1] cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G[sub 1] phase, suggesting that such G[sub 1] phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

A C. elegans mutant that lives twice as long as wild type.

PubMed

Kenyon, C; Chang, J; Gensch, E; Rudner, A; Tabtiang, R

1993-12-02

We have found that mutations in the gene daf-2 can cause fertile, active, adult Caenorhabditis elegans hermaphrodites to live more than twice as long as wild type. This lifespan extension, the largest yet reported in any organism, requires the activity of a second gene, daf-16. Both genes also regulate formation of the dauer larva, a developmentally arrested larval form that is induced by crowding and starvation and is very long-lived. Our findings raise the possibility that the longevity of the dauer is not simply a consequence of its arrested growth, but instead results from a regulated lifespan extension mechanism that can be uncoupled from other aspects of dauer formation. daf-2 and daf-16 provide entry points into understanding how lifespan can be extended.

What Is a Growth Disorder? (For Parents)

MedlinePlus

... hormone, which is essential for normal bone growth. Turner syndrome , one of the most common genetic growth disorders, ... chromosome. In addition to short stature, girls with Turner syndrome usually don't undergo normal sexual development because ...