keyword
MENU ▼
Read by QxMD icon Read
search

Telomerase

keyword
https://www.readbyqxmd.com/read/27911794/activation-of-mutant-tert-promoter-by-ras-erk-signaling-is-a-key-step-in-malignant-progression-of-braf-mutant-human-melanomas
#1
Yinghui Li, Hui Shan Cheng, Wee Joo Chng, Vinay Tergaonkar
Although activating BRAF/NRAS mutations are frequently seen in melanomas, they are not sufficient to drive malignant transformation and require additional events. Frequent co-occurrence of mutations in the promoter for telomerase reverse transcriptase (TERT), along with BRAF alterations, has recently been noted and correlated with poorer prognosis, implicating a functional link between BRAF signaling and telomerase reactivation in melanomas. Here, we report that RAS-ERK signaling in BRAF mutant melanomas is critical for regulating active chromatin state and recruitment of RNA polymerase II at mutant TERT promoters...
November 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27908660/targeting-of-multiple-senescence-promoting-genes-and-signaling-pathways-by-triptonide-induces-complete-senescence-of-acute-myeloid-leukemia-cells
#2
Yanyan Pan, Mei Meng, Nana Zheng, Zhifei Cao, Ping Yang, Xiaodong Xi, Quansheng Zhou
Leukemia cells aberrantly overexpress senescence-suppression telomerase reverse transcriptase (TERT) and down-regulate key senescence-promoting genes to escape complete senescence, resulting in immortalization and malignant progression. Accordingly, induction of complete senescence is a sensible strategy for anti-leukemia therapy. However, effective senescence-based anti-leukemia drugs with low toxicity are currently lacking. In this study, we found that triptonide (chemical name diterpene triepoxide), a small molecule derived from the herb Tripterygium wilfordii Hook, strongly induced complete senescence in cultured acute myeloid leukemia (AML) cell lines, and potently inhibited growth and colony formation of U937 and HL-60 AML cell line with IC50 values of 7...
November 28, 2016: Biochemical Pharmacology
https://www.readbyqxmd.com/read/27904002/diffuse-mesangial-sclerosis-in-a-child-with-dyskeratosis-congenita-leading-to-end-stage-renal-disease
#3
Abidi Kamel, Taha Sayari, Manel Jellouli, Yousra Hammi, Rim Ghoucha Louzir, Tahar Gargah
Dyskeratosis congenita (DC) is a very rare inherited disorder. It is caused by dysfunction of telomere maintenance. It involves RNA telomerase components relevant to various mutations leading to a classic triad of physical findings consisting of nail dystrophy of the hands and feet, mucosal leukoplakia, and reticular pigmentation of the skin, most commonly on the head, neck, and trunk. Bone marrow failure along with pulmonary complications and malignancies are all common causes of premature death in patients with DC as well as other abnormalities...
November 2016: Iranian Journal of Kidney Diseases
https://www.readbyqxmd.com/read/27903905/human-mlh1-suppresses-the-insertion-of-telomeric-sequences-at-intra-chromosomal-sites-in-telomerase-expressing-cells
#4
Pingping Jia, Megan Chastain, Ying Zou, Chengtao Her, Weihang Chai
Aberrant formation of interstitial telomeric sequences (ITSs) promotes genome instabilities. However, it is unclear how aberrant ITS formation is suppressed in human cells. Here, we report that MLH1, a key protein involved in mismatch repair (MMR), suppresses telomeric sequence insertion (TSI) at intra-chromosomal regions. The frequency of TSI can be elevated by double-strand break (DSB) inducer and abolished by ATM/ATR inhibition. Suppression of TSI requires MLH1 recruitment to DSBs, indicating that MLH1's role in DSB response/repair is important for suppressing TSI...
November 29, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27903649/structural-mechanism-underpinning-cross-reactivity-of-a-cd8-t-cell-clone-that-recognises-a-peptide-derived-from-human-telomerase-reverse-transcriptase
#5
David K Cole, Hugo A van den Berg, Angharad Lloyd, Michael D Crowther, Konrad Beck, Julia Ekeruche-Makinde, John J Miles, Anna M Bulek, Garry Dolton, Andrea J Schauenburg, Aaron Wall, Anna Fuller, Mathew Clement, Bruno Laugel, Pierre J Rizkallah, Linda Wooldridge, Andrew K Sewell
T-cell cross-reactivity is essential for effective immune surveillance, but has also been implicated as a pathway to autoimmunity. Previous studies have demonstrated that T-cell receptors (TCRs) that focus on a minimal motif within the peptide are able to facilitate a high level of T-cell cross-reactivity. However, the structural database shows that most TCRs exhibit less focussed antigen binding involving contact with more peptide residues. To further explore the structural features that allow the clonally expressed TCR to functionally engage with multiple peptide-major histocompatibility complexes (pMHCs), we examined the ILA1 CD8+ T-cell clone that responds to a peptide sequence derived from human telomerase reverse transcriptase (hTERT)...
November 30, 2016: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/27901163/synthesis-and-biological-evaluation-of-simplified-pironetin-analogues-with-modifications-in-the-side-chain-and-the-lactone-ring
#6
Steven Roldán, Adrià Cardona, Laura Conesa, Juan Murga, Eva Falomir, Miguel Carda, J Alberto Marco
The preparation of several new analogues of the natural dihydropyrone pironetin is described. They differ from the natural product mainly in the nature of the side chain and the lactone ring. Their cytotoxic activity has been measured. In addition, their interaction with tubulin, their ability to inhibit the secretion of the vascular endothelial growth factor (VEGF) and the expression of angiogenesis and telomerase-related genes have been determined. Unexpectedly, and unlike pironetin, the lactones studied in this work do not interact with tubulin...
November 30, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27901098/tumor-specific-delivery-of-biologics-by-a-novel-t-cell-line-hozot
#7
Teppei Onishi, Hiroshi Tazawa, Yuuri Hashimoto, Makoto Takeuchi, Takeshi Otani, Shuji Nakamura, Fuminori Sakurai, Hiroyuki Mizuguchi, Hiroyuki Kishimoto, Yuzo Umeda, Yasuhiro Shirakawa, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara
"Cell-in-cell" denotes an invasive phenotype in which one cell actively internalizes in another. The novel human T-cell line HOZOT, established from human umbilical cord blood, was shown to penetrate a variety of human cancer cells but not normal cells. Oncolytic viruses are emerging as biological therapies for human cancers; however, efficient viral delivery is limited by a lack of tumor-specific homing and presence of pre-existing or therapy-induced neutralizing antibodies. Here, we report a new, intriguing approach using HOZOT cells to transmit biologics such as oncolytic viruses into human cancer cells by cell-in-cell invasion...
November 30, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27900472/tissue-specific-expression-of-telomerase-reverse-transcriptase-gene-variants-in-nicotiana-tabacum
#8
Jana Fišerová Jurečková, Eva Sýkorová, Said Hafidh, David Honys, Jiří Fajkus, Miloslava Fojtová
In tobacco, three sequence variants of the TERT gene have been described. We revealed unbalanced levels of TERT variant transcripts in vegetative tobacco tissues and enhanced TERT transcription and telomerase activity in reproductive tissues. Telomerase is a ribonucleoprotein complex responsible for the maintenance of telomeres, structures delimiting ends of linear eukaryotic chromosomes. In the Nicotiana tabacum (tobacco) allotetraploid plant, three sequence variants (paralogs) of the gene coding for the telomerase reverse transcriptase subunit (TERT) have been described, two of them derived from the maternal N...
November 29, 2016: Planta
https://www.readbyqxmd.com/read/27900047/microrna-138-inhibits-proliferation-migration-and-invasion-through-targeting-htert-in-cervical-cancer
#9
Na Zhou, Dan Fei, Shan Zong, Mingyue Zhang, Ying Yue
A growing body of evidence suggests that microRNA-138 (miR-138) functions as a tumor suppressor, and is involved in tumor initiation, development and metastasis in certain types of human cancers. However, the function and underlying molecular mechanism of miR-138 in cervical cancer remains unclear. Therefore, the purpose of the present study was to investigate the clinical significance of miR-138 expression in cervical cancer, and to evaluate its role and underlying mechanisms in cervical cancer. The present study indicated that miR-138 expression was significantly downregulated in cervical cancer tissues and cell lines, and that the low miR-138 expression was negatively associated with advanced FIGO stage and lymph node metastasis (P<0...
November 2016: Oncology Letters
https://www.readbyqxmd.com/read/27899638/structure-and-folding-of-the-tetrahymena-telomerase-rna-pseudoknot
#10
Darian D Cash, Juli Feigon
Telomerase maintains telomere length at the ends of linear chromosomes using an integral telomerase RNA (TER) and telomerase reverse transcriptase (TERT). An essential part of TER is the template/pseudoknot domain (t/PK) which includes the template, for adding telomeric repeats, template boundary element (TBE), and pseudoknot, enclosed in a circle by stem 1. The Tetrahymena telomerase holoenzyme catalytic core (p65-TER-TERT) was recently modeled in our 9 Å resolution cryo-electron microscopy map by fitting protein and TER domains, including a solution NMR structure of the Tetrahymena pseudoknot...
November 29, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27899264/cyclic-ferrocenylnaphthalene-diimide-derivative-as-a-new-class-of-g-quadruplex-dna-binding-ligand
#11
Md Monirul Islam, Shinobu Sato, Shingo Shinozaki, Shigeori Takenaka
To identify an effective ligand that binds to a G-quadruplex structure but not a double-stranded DNA (dsDNA), a set of biophysical and biochemical experiments were carried out using newly synthesized cyclic ferrocenylnaphthalene diimide (cFNDI, 1) or the non-cyclic derivative (2) with various structures of G-quadruplex DNAs and dsDNA. Compound 1 bound strongly to G-quadruplexes DNAs (10(6)M(-1) order) with diminished binding to dsDNA (10(4)M(-1) order) in 100mM AcOH-AcOK buffer (pH 5.5) containing 100mM KCl...
November 15, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27898217/increased-telomerase-reverse-transcriptase-expression-associates-with-spontaneous-exit-from-m-ii-arrest-in-rat-eggs
#12
Shilpa Prasad, Shail K Chaube
In mammals, postovulatory egg aging deteriorates egg quality possibly by mediating spontaneous exit from metaphase-II (M-II) arrest and/or inducing apoptosis. To test this possibility, present study was designed to investigate telomerase reverse transcriptase (TERT) expression, Bcl2 expression, and DNA fragmentation during postovulatory egg aging in vivo, as well as in vitro. Results suggest that postovulatory egg aging induced a time-dependent increase in the number of eggs undergoing spontaneous exit from M-II arrest in vivo, as well as in vitro...
November 29, 2016: Cellular Reprogramming
https://www.readbyqxmd.com/read/27898051/preparation-of-6-8-11-amino-chloro-oxoisoaporphine-and-group-10-metal-complexes-and-evaluation-of-their-in-vitro-and-in-vivo-antitumor-activity
#13
Qi-Pin Qin, Jiao-Lan Qin, Ting Meng, Gui-Ai Yang, Zu-Zhuang Wei, Yan-Cheng Liu, Hong Liang, Zhen-Feng Chen
A series of group-10 metal complexes 1-14 of oxoisoaporphine derivatives were designed and synthesized. 1-14 were more selectively cytotoxic to Hep-G2 cells comparing with normal liver cells. In vitro cytotoxicity results showed that complexes 1-6, 7, 8, 10 and 11, especially 3, were telomerase inhibitors targeting c-myc, telomeric, and bcl-2 G4s and triggered cell senescence and apoptosis; they also caused telomere/DNA damage and S phase arrest. In addition, 1-6 also caused mitochondrial dysfunction. Notably, 3 with 6-amino substituted ligand L(a) exhibited less side effects than 6 with 8-amino substituted ligand L(b) and cisplatin, but similar tumor growth inhibition efficacy in BEL-7402 xenograft model...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27895115/shared-subunits-of-tetrahymena-telomerase-holoenzyme-and-replication-protein-a-have-different-functions-in-different-cellular-complexes
#14
Heather E Upton, Henry Chan, Juli Feigon, Kathleen Collins
In most eukaryotes, telomere maintenance relies on telomeric repeat synthesis by a reverse transcriptase named telomerase. To synthesize telomeric repeats, the catalytic subunit telomerase reverse transcriptase (TERT) uses the RNA subunit (TER) as a template. In the ciliate Tetrahymena thermophila,the telomerase holoenzyme consists of TER, TERT, and eight additional proteins including the telomeric-repeat single-stranded DNA binding protein Teb1 and its heterotrimer partners Teb2 and Teb3. Teb1 is paralogous to the large subunit of the general single-stranded DNA binding heterotrimer Replication Protein A (RPA)...
November 28, 2016: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/27894394/differences-of-cell-surface-marker-expression-between-bone-marrow-and-kidney-derived-murine-mesenchymal-stromal-cells-and-fibroblasts
#15
F Cakiroglu, J W Osbahr, J Kramer, J Rohwedel
Mesenchymal stromal cells (MSC) are undifferentiated, multipotent adult cells with regenerative properties. They are particularly relevant for therapeutic approaches due to the simplicity of their isolation and cultivation. Since MSC show an expression pattern of cell surface marker, which is almost identical to fibroblasts, many attempts have been made to address the similarities and differences between MSC and fibroblasts. In this study we aimed to isolate murine MSC from bone marrow (BM) and kidney to characterize them in comparison to fibroblasts...
October 31, 2016: Cellular and Molecular Biology
https://www.readbyqxmd.com/read/27893990/ferrocenyl-naphthalene-diimides-as-tetraplex-dna-binders
#16
Shinobu Sato, Shigeori Takenaka
Seven ferrocenyl naphthalene diimide (FND) ligands were synthesized. Each had a higher affinity for tetraplex DNA than for either single- or double-stranded DNA. The FND binding affinities were >10(5)M(-1) in 0.10M AcOH-AcONa or AcOH-AcOK (pH5.5) containing 0.10M NaCl or KCl. The FNDs with the highest binding affinities for tetraplex DNA showed 23- or 8-times higher preference for tetraplex DNA than for single- or double-stranded DNA, respectively. The current signals generated from the seven FNDs bound to the tetraplex DNA immobilized on the electrode were found to correlate with the binding affinities of these ligands for the tetraplex DNA...
November 17, 2016: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/27893208/enterolactone-reduces-telomerase-activity-and-levels-of-its-catalytic-subunit-in-breast-cancer-cells
#17
Davod Ilbeigi, Mitra Nourbakhsh, Shahnaz Khaghani, Nahid Einollahi, Nejat kheiripour, Zafar Gholinejad, Mohammad Alaee, Mostafa saberian
Background: Dietary consumption of phytoestrogens including lignans are linked to a lower incidence of breast cancer. Since activation of telomerase is crucial for growth of cancer cells, the aim of this study was to examine the effect of enterolactone (ENL) and enterodiol (END) on this enzyme. Methods: MTT assays were performed to determine the effect of different concentrations of ENL and ENL on cell viability and to determine the effective concentrations of these two compounds for inhibition of cell growth...
January 10, 2016: Asian Pacific Journal of Cancer Prevention: APJCP
https://www.readbyqxmd.com/read/27892716/life-and-cancer-without-telomerase-alt-and-other-strategies-for-making-sure-ends-don-t-meet
#18
Manasi S Apte, Julia Promisel Cooper
While most cancer cells rely on telomerase expression/re-activation for linear chromosome maintenance and sustained proliferation, a significant population of cancers (10-15%) employs telomerase-independent strategies, collectively dubbed Alternative Lengthening of Telomeres (ALT). Most ALT cells relax the usual role of telomeres as inhibitors of local homologous recombination while maintaining the ability of telomeres to prohibit local non-homologous end joining reactions. Here we review current concepts surrounding how ALT telomeres achieve this new balance via alterations in chromatin landscape, DNA damage repair processes and handling of telomeric transcription...
November 28, 2016: Critical Reviews in Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/27891214/one-step-immortalization-of-primary-human-airway-epithelial-cells-capable-of-oncogenic-transformation
#19
Jordan L Smith, Liam C Lee, Abigail Read, Qiuning Li, Bing Yu, Chih-Shia Lee, Ji Luo
BACKGROUND: The ability to transform normal human cells into cancer cells with the introduction of defined genetic alterations is a valuable method for understanding the mechanisms of oncogenesis. Easy establishment of immortalized but non-transformed human cells from various tissues would facilitate these genetic analyses. RESULTS: We report here a simple, one-step immortalization method that involves retroviral vector mediated co-expression of the human telomerase protein and a shRNA targeting the CDKN2A gene locus...
2016: Cell & Bioscience
https://www.readbyqxmd.com/read/27889084/linking-telomere-regulation-to-stem-cell-pluripotency
#20
REVIEW
Lin Liu
Embryonic stem cells (ESCs), somatic cell nuclear transfer ESCs, and induced pluripotent stem cells (iPSCs) represent the most studied group of PSCs. Unlimited self-renewal without incurring chromosomal instability and pluripotency are essential for the potential use of PSCs in regenerative therapy. Telomere length maintenance is critical for the unlimited self-renewal, pluripotency, and chromosomal stability of PSCs. While telomerase has a primary role in telomere maintenance, alternative lengthening of telomere pathways involving recombination and epigenetic modifications are also required for telomere length regulation, notably in mouse PSCs...
November 23, 2016: Trends in Genetics: TIG
keyword
keyword
6048
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"