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Beltrami Antonio Paolo - - 2011
Cellular senescence is a specialized form of growth arrest, confined to mitotic cells, induced by various stressful stimuli and characterized by a permanent growth arrest, resistance to apoptosis, an altered pattern of gene expression and the expression of some markers that are characteristic, although not exclusive, to the senescent state. ...
Hsieh Yu-Shan - - 2011
Trophocytes and fat cells are distributed around the abdominal segments in honeybees (Apis mellifera). Whether these cells are a good model for cellular senescence studies is unknown. Here we used histochemical, biochemical, and genetic techniques to investigate the fluctuation of age-related molecules in trophocytes and fat cells of newly emerged ...
Kenmotsu M - - 2010
To investigate the characteristics of side population (SP) cells derived from the dental pulp of young and aged rats. Maxillary and mandibular incisors were extracted from 5-week-old (young) rats and 60- to 80-week-old (aged) rats. Coronal pulp tissue was removed mechanically, and single-cell suspensions were prepared using collagenase and dispase. ...
Zhang Hao - - 2010
Telomere stability is believed to be related to aging and tumorigenesis. Besides telomerase, telomere length is also regulated by several telomere-specific binding proteins. Tankyrase 1, a telomeric poly(ADP-ribose) polymerase (PARP), elongates telomere length by inhibiting TRF1 binding to telomeres. In order to study the synergistic action of tankyrase 1 and ...
Yip Yim-Ling - - 2010
Cell immortalization is regarded as an early and pre-requisite step in tumor development. Defining the specific genetic events involved in cell immortalization may provide insights into the early events of carcinogenesis. Nasopharyngeal carcinoma is common among the Southern Chinese population. Epstein-Barr virus (EBV) infection is associated closely with nasopharyngeal carcinoma. ...
Romanov V S - - 2010
Cell senescence is characterized by senescent morphology and permanent loss of proliferative potential. HDAC inhibitors (HDACI) induce senescence and/or apoptosis in many types of tumor cells. Here, we studied the role of cyclin-kinase inhibitor p21(waf1) (Cdkn1n gene) in cell cycle arrest, senescence markers (cell hypertrophy, SA-βGal staining and accumulation of ...
Jeang Kuan-Teh - - 2010
The mechanism of HTLV-1 transformation of cells to Adult T cell leukemia (ATL) remains not fully understood. Currently, the viral Tax oncoprotein is known to be required to initiate transformation. Emerging evidence suggests that Tax is not needed to maintain the transformed ATL phenotype. Recent studies have shown that HTLV-1 ...
Ju Yeun-Jin - - 2010
A combination of a radiotherapeutic regimen with telomerase inhibition is valuable when tumor cells are to be sensitized to radiation. Here, we describe cell clones unresponsive to radiosensitization after telomere shortening. After extensive division of individual transformed clones of mTERC-/- cells, about 22% of clones were unresponsive to radiosensitization even ...
Morbach H - - 2010
The composition of the peripheral blood lymphocyte compartment underlies developmental changes during ontogeny. Recently, several new B cell populations have been characterized which were suggested to develop in an age-dependent manner. However, age-dependent reference values for distinct B cell populations have rarely been reported. Therefore, we have characterized developmental changes ...
Hernroth Bodil - - 2010
In contrast to most vertebrates, invertebrate deuterostome echinoderms, such as the sea star Asterias rubens, undergo regeneration of lost body parts. The current hypothesis suggests that differentiated cells are the main source for regenerating arm in sea stars, but there is little information regarding the origin and identity of these ...
Kim Sung Young - - 2010
Hypo-responsiveness to growth factors is a fundamental feature of cellular senescence. In this study, we found markedly decreased level of Nup107, a key scaffold protein in nuclear pore complex assembly, in senescent human diploid fibroblasts as well as in organs of aged mice. Depletion of Nup107 by specific siRNA in ...
Lee Inkyoung - - 2010
Senescence is an important determinant of treatment outcome in cancer therapy. In the present study, we show that knockdown of the inwardly rectifying K(+) channel Kir2.2 induced growth arrest without additional cellular stress in cancer cells lacking functional p53, p16, and/or Rb. Kir2.2 knockdown also induced senescence-associated β-galactosidase activity and ...
Liu Weiping - - 2010
High-affinity Na(+)-dependent dicarboxylate cotransporter (NaDC3) can transport Krebs cycle intermediates into cells. Our previous study has shown that NaDC3 promotes cellular senescence, but its mechanism is not clear. It is known that when the concentration of intermediates in Krebs cycle is increased, NAD(+)/NADH ratio will be decreased. NAD(+)-dependent histone deacetylase ...
Wang Chunfang C Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, - - 2010
Dietary restriction (DR) extends the lifespan of a wide variety of species and reduces the incidence of major age-related diseases. Cell senescence has been proposed as one causal mechanism for tissue and organism ageing. We show for the first time that adult-onset, short-term DR reduced frequencies of senescent cells in ...
Rao Yerra Koteswara - - 2010
High telomerase activity (TA) is detected in most cancer cells; and thus, TA inhibition by drug or dietary food components is a new strategy for cancer prevention. In this report, we examined the effects of fourteen natural or synthetic compounds on TA in human lung adenocarcinoma A549 cells. The results ...
Kim Tae Rim - - 2010
Smooth muscle protein 22-alpha (SM22α) 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 SM22α overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 ...
Knecht Hans - - 2010
Recent research using an innovative 3D quantitative FISH approach of nuclear remodelling associated with the transition from mononuclear Hodgkin to diagnostic multinuclear Reed-Sternberg cells revealed profound changes in the 3D nuclear organization of telomeres. Analogous 3D telomere dynamics were identified in Hodgkin's lymphoma derived cell-lines and diagnostic patient biopsies. These ...
Shi Yi-zhen - - 2010
The sodium-iodide symporter (NIS) protein can mediate the active radioiodine uptake. The human telomerase reverse transcriptase (hTERT) promoter is known to be selectively reactivated in majority of tumors and hence could be used for tumor targeting. We constructed a recombinant adenovirus containing the human sodium iodide symporter (hNIS) gene directed ...
Wheaton Keith - - 2010
Cellular senescence limits the replicative capacity of normal cells and acts as an intrinsic barrier that protects against the development of cancer. Telomere shortening-induced replicative senescence is dependent on the ATM-p53-p21 pathway but additional genes likely contribute to senescence. Here, we show that the p53-responsive gene BTG2 plays an essential ...
Ngo Hien-Ping - - 2010
Maintenance of telomere capping is absolutely essential to the survival of eukaryotic cells. Telomere capping proteins, such as Cdc13 and POT1, are essential for the viability of budding yeast and mammalian cells, respectively. Here we identify, for the first time, three genetic modifications that allow budding yeast cells to survive ...
Luning Prak Eline T - - 2011
Abstract There are few studies of the developmental changes in B-cell subsets in children. Recent data from adult populations demonstrate that alterations to B-cell subsets have functional consequences and can be helpful diagnostically. Comparable studies in children have been hindered by the lack of normative data and by significant changes ...
Burton D G A - - 2010
The accumulation of senescent cells within tissues can potentially lead to biological dysfunction and manifestation of disease associated with ageing. The majority of senescent cells display a commonly altered secretome similar to a wound healing response (termed the senescence-associated secretory phenotype or SASP), which could have deleterious implications on the ...
Chen Jeff Yi-Fu - - 2010
the aims of the study are to investigate the additive effect of exogenous short-carbon chain phospholipids, C(2)-ceramide, on an anti-cancer drug paclitaxel (PTX)-induced senescence of human non-small cell lung cancer (NSCLC) cells deficient in functional p53 and p16, and to examine whether mitogen-activated protein kinase (MAPK) plays a role in ...
Zhou Fu-Xiang - - 2010
To achieve a more complete understanding of the molecular mechanisms underlying tumor radioresistance, we established a radioresistant cell line from the human larynx squamous cell carcinoma cell line Hep-2 after long-term radiation induction. The biological features of the resulting cell lines were characterized. cDNA microarray technology was used to measure ...
Vodenicharov Momchil D - - 2010
The assembly of a protective cap onto the telomeres of eukaryotic chromosomes suppresses genomic instability through inhibition of DNA repair activities that normally process accidental DNA breaks. We show here that the essential Cdc13-Stn1-Ten1 complex is entirely dispensable for telomere protection in non-dividing cells. However, Yku and Rap1 become crucially ...
McDuff Fiona K E - - 2011
Aberrant oncogenic signals are typically counteracted by anti-proliferative mechanisms governed principally by the p53 and Rb tumour-suppressor proteins. Apoptosis is firmly established as a potent anti-proliferative mechanism to prevent tumour growth but it is only in recent years that oncogene-induced senescence has achieved similar recognition. Senescence is defined as an ...
Tomlinson Rebecca L - - 2010
The intranuclear trafficking of human telomerase involves a dynamic interplay between multiple nuclear sites, most notably Cajal bodies and telomeres. Cajal bodies are proposed to serve as sites of telomerase maturation, storage, and assembly, as well as to function in the cell cycle-regulated delivery of telomerase to telomeres in human ...
Kim You-Mie - - 2010
Increased cell mass is one of the characteristics of senescent cells, but this event has not been clearly defined. When subcellular organellar mass was estimated with organelle-specific fluorescence dyes, we observed that most membranous organelles progressively increase in mass during cell senescence. This increase was accompanied by an increase in ...
Vinnars Marie-Therese N - - 2010
Hofbauer cells are placental macrophages found in chorionic villous stroma; they express classic monocyte/macrophage markers, such as CD68. Little is known about their participation in placental disease and immunologic interactions at the placental interface. The aim of this study was to quantify the amount of Hofbauer cells in placentas complicated, ...
Guo Xiao-Fei - - 2010
Telomeres are essential for chromosome stability and the regulation of the replicative life-span of somatic cells. Many studies showed that exogenous telomeric repeats could activate p53 protein. It is not known how cell dysfunction is induced by telomeric plasmids. A covalent closed circular (ccc) double-stranded plasmid containing (TTAGGG)(96) repeats (pRST5) ...
Hsu Hui-Chen - - 2010
Although the phenotype of T-cell senescence has been extensively investigated, few studies have analyzed the factors that promote the generation and maintenance of naïve and memory T cells that exist throughout the lifespan of the individuals. Unlike senescent T cells, naïve and memory T cells are able to participate in ...
Dewar James M - - 2010
In this issue of Molecular Cell, Faure et al. (2010) establish a critical role for the Mre11 complex in the recruitment of telomerase to leading- but not lagging-strand telomeres of budding yeast.
Hájek Miroslav - - 2010
We have previously shown that PMEG diphosphate (PMEGpp) and PMEDAP diphosphate (PMEDAPpp) inhibit the enzymatic activity of human telomerase in a cell-free assay. Here, we investigated the ability of PMEG and PMEDAP to induce telomere shortening and telomerase inhibition at both transcriptional and activity level in T-lymphoblastic leukemia cells CCRF-CEM ...
Liu Jun-Ping - - 2010
Telomerase, an enzyme complex that binds the chromosome ends (telomeres) and maintains telomere length and integrity, is present in germ cells, proliferative granulosa cells, germline stem cells, and neoplastic cells in the ovary, but it is absent in differentiated or aged cells. Activation of telomerase in the ovary underpins both ...
Zhao Bo - - 2010
Telomerase-negative immortalized cells maintain their telomeres through a telomerase-independent pathway termed alternative lengthening of telomeres (ALT). The mechanism of ALT is based on homologous recombination (HR). A hallmark of ALT cells is presence of a nuclear structure termed ALT-associated promyelocytic leukemia body (APB). Here, we demonstrated that hRAD21, an important ...
Raghuram Gorantla Venkata - - 2010
Ovarian surface epithelium is under constant physiological pressure to maintain its integrity. Environmental toxic exposure can contribute to degenerative pathologies including ovarian cancer. Based on our current understanding, we aimed at listing mechanistic insights that contribute to ovarian carcinogenesis after exposure to methyl isocyanate, an ubiquitous environmental pollutant. Ovarian epithelial ...
Takubo Kaiyo - - 2010
Chromosomal and genomic instability due to telomere dysfunction is known to play an important role in carcinogenesis. To study telomere dysfunction in the surrounding background epithelium of squamous cell carcinoma in situ (CIS) of the oesophagus, we measured telomere lengths of basal and parabasal cells of epithelia with and without ...
Moon Dong-Oh - - 2010
Up-regulation of telomerase activity is associated with immortalization and unlimited cell division in most cancer cells. Therefore, telomerase represents a particularly attractive target for anticancer therapy. Recent reports have suggested that beta-lapachone (LAPA), the product of the South American Tabebuia avellanedae tree, inhibits growth of tumor cells. However, the underlying ...
De Vos W H - - 2010
Telomeres are the complex end structures that confer functional integrity and positional stability to human chromosomes. Telomere research has long been dominated by length measurements and biochemical analyses. Recently, interest has shifted towards the role of their three-dimensional organization and dynamics within the nuclear volume. In the mammalian interphase nucleus, ...
Korotchkina Lioubov G - - 2010
Transient induction of p53 can cause reversible quiescence and irreversible senescence. Using nutlin-3a (a small molecule that activates p53 without causing DNA damage), we have previously identified cell lines in which nutlin-3a caused quiescence. Importantly, nutlin-3a caused quiescence by actively suppressing the senescence program (while still causing cell cycle arrest). ...
Wang Qin - - 2011
Therapy-induced accelerated cellular senescence (ACS) is a reversible tumor response to chemotherapy that is likely detrimental to the overall therapeutic efficacy of cancer treatment. To further understand the mechanism by which cancer cells can escape the sustained cell cycle arrest in ACS, we established a tissue culture model, in which ...
Ho Chin-Chin - - 2011
Metastasis suppressors and associated other regulators of cell motility play a critical initial role in tumor invasion and metastases. Benzyl isothiocyanate (BITC) is a hydrolysis compound of glucotropaeolin in dietary cruciferous vegetables. BITC has been found to exhibit prevention of cancers in laboratory animals and might also be chemoprotective in ...
Mariani Melissa M - - 2010
Originally identified in cultured cells, oncogenic cellular senescence is a growth-arrest mechanism which may inhibit tumor development by limiting the ability of cells to divide. However, literature shows that these cells secrete tumor-inducing and tumor-suppressing proteins leading to poor prognosis. Understanding the progression of oncogenic cellular senescence and associated mechanisms ...
Oh W - - 2010
In this study, we identified posttranslational regulation of human telomerase reverse-transcriptase (hTERT) by the E3 ligase Hdm2. The telomerase activity generated by exogenous hTERT in U2OS cells was reduced on adriamycin treatment. The overexpressed levels of hTERT were also decreased under the same conditions. These processes were reversed by treatment ...
Kikuchi Ikue - - 2010
Adriamycin, an anthracycline antibiotic, has been used for the treatment of various types of tumours. Adriamycin induces at least two distinct types of growth repression, such as senescence and apoptosis, in a concentration-dependent manner. Cellular senescence is a condition in which cells are unable to proliferate further, and senescent cells ...
Liu Yan - - 2010
Telomerase activity is found in various cell types including stem cells, neoplastic cells, and immortalized cells, suggesting a close association with their proliferation capacity. The telomeric repeat amplification protocol (TRAP) has been traditionally used to detect semi-quantitatively the telomerase activity by polyacrylamide gel electrophoresis (PAGE), which is difficult to apply ...
Vaziri H - - 2010
AIM: To determine whether transcriptional reprogramming is capable of reversing the developmental aging of normal human somatic cells to an embryonic state. MATERIALS & METHODS: An isogenic system was utilized to facilitate an accurate assessment of the reprogramming of telomere restriction fragment (TRF) length of aged differentiated cells to that ...
Joseph Immanual S - - 2010
Preventing the formation of dysfunctional telomeres is essential for genomic stability. In most organisms, the ribo-nucleoprotein reverse transcriptase telomerase is responsible for telomere GT-strand elongation. However, in telomerase-negative cells, low-frequency recombination mechanisms can avert lethality by elongating critically short telomeres. This study focuses on the involvement of the budding yeast ...
Chen W - - 2010
BACKGROUND AND PURPOSE: Telomere length must be maintained throughout cancer cell progression and proliferation. In most tumours, telomerase activity maintains telomere length. Therefore, telomerase is a target for cancer treatments. However, some cancer cells maintain telomere length through an alternative mechanism termed 'alternative lengthening of telomeres'. To determine how telomerase ...
Kujuro Yuki - - 2010
Mammalian aging is thought to be partially caused by the diminished capacity of stem/precursor cells to undergo self-renewing divisions. Although many cell-cycle regulators are involved in this process, it is unknown to what extent cell senescence, first identified as irreversible growth arrest in vitro, contributes to the aging process. Here, ...
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