scholarly journals Fungal Ku prevents permanent cell cycle arrest by suppressing DNA damage signaling at telomeres

2015 ◽  
Vol 43 (4) ◽  
pp. 2138-2151 ◽  
Author(s):  
Carmen de Sena-Tomás ◽  
Eun Young Yu ◽  
Arturo Calzada ◽  
William K. Holloman ◽  
Neal F. Lue ◽  
...  
Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 466 ◽  
Author(s):  
Harikrishnareddy Paluvai ◽  
Eros Di Giorgio ◽  
Claudio Brancolini

Senescence is the end point of a complex cellular response that proceeds through a set of highly regulated steps. Initially, the permanent cell-cycle arrest that characterizes senescence is a pro-survival response to irreparable DNA damage. The maintenance of this prolonged condition requires the adaptation of the cells to an unfavorable, demanding and stressful microenvironment. This adaptation is orchestrated through a deep epigenetic resetting. A first wave of epigenetic changes builds a dam on irreparable DNA damage and sustains the pro-survival response and the cell-cycle arrest. Later on, a second wave of epigenetic modifications allows the genomic reorganization to sustain the transcription of pro-inflammatory genes. The balanced epigenetic dynamism of senescent cells influences physiological processes, such as differentiation, embryogenesis and aging, while its alteration leads to cancer, neurodegeneration and premature aging. Here we provide an overview of the most relevant histone modifications, which characterize senescence, aging and the activation of a prolonged DNA damage response.


2021 ◽  
Vol 245 ◽  
pp. 03051
Author(s):  
Hanyi Jia

A mitotic cell that rests in permanent cell cycle arrest without the ability to divide is considered as a senescent cell. Cellular senescence is essential to limit the function of cells with heavy DNA damages. The lack of senescence is in favour of tumorigenesis, whereas the accumulation of senescent cells in tissues is likely to induce ageing and age-related pathologies on the organismal level. Understanding of cellular senescence is thus critical to both cancer and ageing studies. Senescence, essentially permanent cell cycle arrest, is one of the results of DNA damage response, such as the ataxia telangiectasia mutated and the ataxia telangiectasia and Rad3-related signaling pathways. In other cases, mild DNA damages can usually be repaired after DNA damage response, while the cells with heavy damages on DNA end in apoptosis. The damage to the special structure of telomere, however, prone to result in permanent cell cycle arrest after activation of DNA damage response. In fact, a few previous pieces of research on ageing have largely focused on telomere and considered it a primary contributor to different types of senescence. For instance, its reduction in length after each replication turns on a timer for replicative senescence, and its tandem repeats specific to binding proteins makes it susceptible to DNA damage from oxidative stress, and thus stress-induced premature senescence. In most of the senescent cells, the accumulation of biomarkers is found around the telomere which has either its tail structure disassembled or damage foci exposed on the tandem repeats. In this review, among several types of senescence, I will investigate two of the most common and widely discussed types in eukaryotic cells -replicative senescence and stress-induced premature senescence - in terms of their mechanism, relationship with telomere, and implication to organismal ageing.


Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769501 ◽  
Author(s):  
Paweł Szymański ◽  
Paulina Olszewska ◽  
Elżbieta Mikiciuk-Olasik ◽  
Antoni Różalski ◽  
Agnieszka Maszewska ◽  
...  

Lung cancer is still the leading cause of cancer-related death worldwide, indicating a necessity to develop more effective therapy. Acridine derivatives are potential anticancer agents due to their ability to intercalate DNA as well as inhibit enzymes involved in replication and transcription. Recently, we have evaluated anticancer activity of 32 novel acridine-based compounds. We found that the most effective were tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid containing eight and nine carbon atoms in the aliphatic chain. The aim of this study was to determine the molecular mechanisms of compounds-induced cell cycle arrest and apoptosis in human lung adenocarcinoma cells. All compounds activated Ataxia telangiectasia mutated kinase and phosphorylated histone H2A.X at Ser139 indicating DNA damage. Treatment of cells with the compounds increased phosphorylation and accumulation of p53 that regulate cell cycle as well as apoptosis. All compounds induced G0/1 cell cycle arrest by phosphorylation of cyclin-dependent kinase 2 at Tyr15 resulting in attenuation of the kinase activity. In addition, cyclopentaquinoline derivatives induced expression of cyclin-dependent kinase 2 inhibitor, p21; however, tetrahydroacridine derivatives had no significant effect on p21. Moreover, all compounds decreased the mitochondrial membrane potential accompanied by increased expression of Bax and down-regulation of Bcl-2, suggesting activation of the mitochondrial pathway. All compounds also significantly attenuated the migration rates of lung cancer cells. Collectively, our findings suggest a central role of activation of DNA damage signaling in response to new acridine derivatives treatment to induce cell cycle arrest and apoptosis in cancer cells and provide support for their further development as potential drug candidates.


2012 ◽  
Vol 287 (10) ◽  
pp. 7399-7410 ◽  
Author(s):  
Alan Baer ◽  
Dana Austin ◽  
Aarthi Narayanan ◽  
Taissia Popova ◽  
Markus Kainulainen ◽  
...  

2020 ◽  
Vol 48 (11) ◽  
pp. 6092-6107
Author(s):  
Candice Qiu Xia Yam ◽  
David Boy Chia ◽  
Idina Shi ◽  
Hong Hwa Lim ◽  
Uttam Surana

Abstract The DNA damage checkpoint halts cell cycle progression in G2 in response to genotoxic insults. Central to the execution of cell cycle arrest is the checkpoint-induced stabilization of securin-separase complex (yeast Pds1-Esp1). The checkpoint kinases Chk1 and Chk2 (yeast Chk1 and Rad53) are thought to critically contribute to the stability of securin-separase complex by phosphorylation of securin, rendering it resistant to proteolytic destruction by the anaphase promoting complex (APC). Dun1, a Rad53 paralog related to Chk2, is also essential for checkpoint-imposed arrest. Dun1 is required for the DNA damage-induced transcription of DNA repair genes; however, its role in the execution of cell cycle arrest remains unknown. Here, we show that Dun1′s role in checkpoint arrest is independent of its involvement in the transcription of repair genes. Instead, Dun1 is necessary to prevent Pds1 destruction during DNA damage in that the Dun1-deficient cells degrade Pds1, escape G2 arrest and undergo mitosis despite the presence of checkpoint-active Chk1 and Rad53. Interestingly, proteolytic degradation of Pds1 in the absence of Dun1 is mediated not by APC but by the HECT domain-containing E3 ligase Rsp5. Our results suggest a regulatory scheme in which Dun1 prevents chromosome segregation during DNA damage by inhibiting Rsp5-mediated proteolytic degradation of securin Pds1.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1453
Author(s):  
Haoran Wang ◽  
Jianhua Wei ◽  
Hong Jiang ◽  
Ye Zhang ◽  
Caina Jiang ◽  
...  

The use of cisplatin is severely limited by its toxic side-effects, which has spurred chemists to employ different strategies in the development of new metal-based anticancer agents. Here, three novel dehydroabietyl piperazine dithiocarbamate ruthenium (II) polypyridyl complexes (6a–6c) were synthesized as antitumor agents. Compounds 6a and 6c exhibited better in vitro antiproliferative activity against seven tumor cell lines than cisplatin, they displayed no evident resistance in the cisplatin-resistant cell line A549/DPP. Importantly, 6a effectively inhibited tumor growth in the T-24 xenograft mouse model in comparison with cisplatin. Gel electrophoresis assay indicated that DNA was the potential targets of 6a and 6c, and the upregulation of p-H2AX confirmed this result. Cell cycle arrest studies demonstrated that 6a and 6c arrested the cell cycle at G1 phase, accompanied by the upregulation of the expression levels of the antioncogene p27 and the down-regulation of the expression levels of cyclin E. In addition, 6a and 6c caused the apoptosis of tumor cells along with the upregulation of the expression of Bax, caspase-9, cytochrome c, intracellular Ca2+ release, reactive oxygen species (ROS) generation and the downregulation of Bcl-2. These mechanistic study results suggested that 6a and 6c exerted their antitumor activity by inducing DNA damage, and consequently causing G1 stage arrest and the induction of apoptosis.


2002 ◽  
Vol 277 (23) ◽  
pp. 21110 ◽  
Author(s):  
Damu Tang ◽  
Dongcheng Wu ◽  
Atsushi Hirao ◽  
Jill M. Lahti ◽  
Lieqi Liu ◽  
...  

2021 ◽  
Vol 32 ◽  
pp. S346
Author(s):  
Md Mohiuddin ◽  
Hideharu Kimura ◽  
Takashi Sone ◽  
Hiroki Matsuoka ◽  
Keigo Saeki ◽  
...  

Molecules ◽  
2012 ◽  
Vol 17 (6) ◽  
pp. 7241-7254 ◽  
Author(s):  
Jing-Iong Yang ◽  
Chi-Chen Yeh ◽  
Jin-Ching Lee ◽  
Szu-Cheng Yi ◽  
Hurng-Wern Huang ◽  
...  

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