scholarly journals Natural Merosesquiterpenes Activate the DNA Damage Response via DNA Strand Break Formation and Trigger Apoptotic Cell Death in p53-Wild-type and Mutant Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3282
Author(s):  
Apisada Jiso ◽  
Philipp Demuth ◽  
Madeleine Bachowsky ◽  
Manuel Haas ◽  
Nina Seiwert ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Cell Death ◽  
Dna Damage Response ◽  
Strand Break ◽  
Wild Type ◽  
Dna Strand Break ◽  
Damage Response ◽  
Dna Strand ◽  
Break Formation

Colorectal cancer (CRC) is a frequently occurring malignant disease with still low survival rates, highlighting the need for novel therapeutics. Merosesquiterpenes are secondary metabolites from marine sponges, which might be useful as antitumor agents. To address this issue, we made use of a compound library comprising 11 isolated merosesquiterpenes. The most cytotoxic compounds were smenospongine > ilimaquinone ≈ dactylospontriol, as shown in different human CRC cell lines. Alkaline Comet assays and γH2AX immunofluorescence microscopy demonstrated DNA strand break formation in CRC cells. Western blot analysis revealed an activation of the DNA damage response with CHK1 phosphorylation, stabilization of p53 and p21, which occurred both in CRC cells with p53 knockout and in p53-mutated CRC cells. This resulted in cell cycle arrest followed by a strong increase in the subG1 population, indicative of apoptosis, and typical morphological alterations. In consistency, cell death measurements showed apoptosis following exposure to merosesquiterpenes. Gene expression studies and analysis of caspase cleavage revealed mitochondrial apoptosis via BAX, BIM, and caspase-9 as the main cell death pathway. Interestingly, the compounds were equally effective in p53-wild-type and p53-mutant CRC cells. Finally, the cytotoxic activity of the merosesquiterpenes was corroborated in intestinal tumor organoids, emphasizing their potential for CRC chemotherapy.

Inactivation of Cdc2 increases the level of apoptosis induced by DNA damage

1995 ◽  
Vol 108 (8) ◽  
pp. 2897-2904 ◽  
Author(s):  
W. Ongkeko ◽  
D.J. Ferguson ◽  
A.L. Harris ◽  
C. Norbury
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Protein Kinase ◽  
Apoptotic Cell ◽  
Mutant Cell ◽  
Strand Break ◽  
Temperature Sensitive ◽  
Dna Strand Break ◽  
Dna Strand ◽  
Inhibitor Compounds

A number of lines of evidence have suggested a possible involvement of the mitosis-promoting protein kinase Cdc2 in the process of apoptotic cell death, and one recent study concluded that premature activation of Cdc2 is required for apoptosis. Here we have used a temperature-sensitive murine Cdc2 mutant cell line and Cdc2 inhibitor compounds to study the effect of inhibition of this protein kinase on apoptosis induced by DNA-damaging drugs. Inhibition of Cdc2 activity before or during exposure to DNA strand break-inducing drugs had the effect of increasing the level of subsequent apoptosis, as assessed by electron microscopy and flow cytometry. We conclude that, far from being required for cell death, a form of mammalian Cdc2 suppresses apoptosis induced by DNA damage. This form of Cdc2 appears to be active in G2-arrested cells and is therefore presumably distinct from the mitosis-promoting Cdc2-cyclin B heterodimer.

Alkylator-Induced DNA Damage Response in Multiple Myeloma (MM) Cells Is Amplified by Histone Deacetylase (HDAC) Inhibition, Resulting in Significant Synergism in Cell Death

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5157-5157
Author(s):  
Choon Kee Lee ◽  
Shuiliang Wang ◽  
Xiaoping Huang ◽  
John Ryder ◽  
Peter Ordentlich ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Cell Lines ◽  
Dna Damage Response ◽  
Strand Break ◽  
Mitotic Catastrophe ◽  
Hdac Inhibition ◽  
Dna Double Strand Break ◽  
Damage Response

Abstract One of the main mechanisms of action of HDAC inhibitors is the transcriptional reactivation of dormant tumor-suppressor genes through acetylation of histones, thereby inducing apoptosis. Treatment with HDACI has also been shown to induce chromatin destabilization in a transcription independent way. In the current study, we sought to determine whether HDAC inhibition induces DNA damage and amplifies alkylator-induced mitotic cell death in both melphalan sensitive- and resistant-MM cell lines (RPMI8226, 8226/LR5). The IC50 values of SNDX275, a class I HDACI agent, and melphalan on the 72-hour MTT assay were 268.05 nM and 245.94 nM in the RPMI8226, and 309.91 nM and 8657.46 nM in the 8226/LR5, respectively. When combined together at clinically attainable concentrations, the combination index by the Chou-Talalay method ranged from 0.27 to 0.75 for the RPMI8226 and from 0.33 to 0.7 for the 8226/LR5, indicating a powerful synergism. For elucidation of molecular mechanisms, MM1S and RPMI8226 cell lines were investigated for apoptosis, histone acetylation, cell cycle analysis, DNA double strand break and DNA damage response serially in 48-hour culture with SNDX-275 at 500 nM and melphalan at 10 μM, alone and in combination. Cleavage of PARP was seen following treatment with each SNDX275 and melphalan, but was highest at 48 hours with the combination of both. Apoptosis was associated with cleavage of caspases of 8, 3 and 9, which was most intense on combination. Melphalan amplified SNDX275-induced acetylation of H3. In cell cycle analysis by flow cytometry, SNDX275 caused an increase in G0-G1 and a decrease in S and G2-M. Cyclin D1, E2F-1 and p53 on western blot were not affected but expression of p21 increased. Melphalan arrested the cell cycle at G2, increased expression of p53 in the RPMI8226 and of p21 in the MM1S. The combination intensified the increase in p21 in both cell lines and in p53 only in the RPMI8226. Phosphorylation of H2AX, a marker of DNA double strand break, increased in a time dependent manner following each drug, along with an increase in phosphorylation of CHK1 and CHK2, indicative of initiation of DNA damage response. The increase in γH2AX and pCHK1 & 2, however, was considerably higher on combination than each drug alone. Furthermore, morphologic assessment of dead cells by the 48 hours of culture revealed a significant increase in mitotic catastrophe on combination in the MM1S: 0% on SNDX275 alone; 10% on melphalan alone; 43.4% on combination. The current study suggests that HDAC inhibition synergizes with melphalan in MM cells and that intensification of DNA damage is one of the mechanisms. Further studies are necessary to understand the role of HDAC inhibition for induction of mitotic catastrophe.

FGF-10 prevents mechanical stretch-induced alveolar epithelial cell DNA damage via MAPK activation

2003 ◽  
Vol 284 (2) ◽  
pp. L350-L359 ◽  
Author(s):  
Daya Upadhyay ◽  
Eduardo Correa-Meyer ◽  
Jacob I. Sznajder ◽  
David W. Kamp
Keyword(s):  
Dna Damage ◽  
Strand Break ◽  
Cyclic Stretch ◽  
Normal Lung ◽  
Alveolar Type ◽  
Mapk Activation ◽  
Alveolar Epithelial ◽  
Dna Strand Break ◽  
Dna Strand ◽  
Break Formation

Cyclic stretch of alveolar epithelial cells (AEC) can alter normal lung barrier function. Fibroblast growth factor-10 (FGF-10), an alveolar type II cell mitogen that is critical for lung development, may have a role in promoting AEC repair. We studied whether cyclic stretch induces AEC DNA damage and whether FGF-10 would be protective. Cyclic stretch (30 min of 30% strain amplitude and 30 cycles/min) caused AEC DNA strand break formation, as assessed by alkaline unwinding technique and DNA nucleosomal fragmentation. Pretreatment of AEC with FGF-10 (10 ng/ml) blocked stretch-induced DNA strand break formation and DNA fragmentation. FGF-10 activated AEC mitogen-activated protein kinase (MAPK), and MAPK inhibitors prevented FGF-10-induced AEC MAPK activation and abolished the protective effects of FGF-10 against stretch-induced DNA damage. In addition, a Grb2-SOS inhibitor (SH3b-p peptide), a RAS inhibitor (farnesyl transferase inhibitor 277), and a RAF-1 inhibitor (forskolin) each prevented FGF-10-induced extracellular signal-regulated kinase (ERK) 1/2 phosphorylation in AEC. Moreover, N17-A549 cells that express a RAS dominant/negative protein prevented the FGF-10-induced ERK1/2 phosphorylation and RAS activation in AEC. We conclude that cyclic stretch causes AEC DNA damage and that FGF-10 attenuates these effects by mechanisms involving MAPK activation via the Grb2-SOS/Ras/RAF-1/ERK1/2 pathway.

scholarly journals Depletion of the DarG antitoxin in Mycobacterium tuberculosis triggers the DNA‐damage response and leads to cell death

2020 ◽  
Vol 114 (4) ◽  
pp. 641-652 ◽  
Author(s):  
Anisha Zaveri ◽  
Ruojun Wang ◽  
Laure Botella ◽  
Ritu Sharma ◽  
Linnan Zhu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Mycobacterium Tuberculosis ◽  
Dna Damage Response ◽  
Damage Response

scholarly journals Sites of Acetylation on Newly Synthesized Histone H4 Are Required for Chromatin Assembly and DNA Damage Response Signaling

2013 ◽  
Vol 33 (16) ◽  
pp. 3286-3298 ◽  
Author(s):  
Zhongqi Ge ◽  
Devi Nair ◽  
Xiaoyan Guan ◽  
Neha Rastogi ◽  
Michael A. Freitas ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Histone H3 ◽  
Model Organism ◽  
Strand Break ◽  
Chromatin Assembly ◽  
Histone H4 ◽  
Histone H4 Acetylation ◽  
Damage Response ◽  
A Site

The best-characterized acetylation of newly synthesized histone H4 is the diacetylation of the NH2-terminal tail on lysines 5 and 12. Despite its evolutionary conservation, this pattern of modification has not been shown to be essential for either viability or chromatin assembly in any model organism. We demonstrate that mutations in histone H4 lysines 5 and 12 in yeast confer hypersensitivity to replication stress and DNA-damaging agents when combined with mutations in histone H4 lysine 91, which has also been found to be a site of acetylation on soluble histone H4. In addition, these mutations confer a dramatic decrease in cell viability when combined with mutations in histone H3 lysine 56. We also show that mutation of the sites of acetylation on newly synthesized histone H4 results in defects in the reassembly of chromatin structure that accompanies the repair of HO-mediated double-strand breaks. This defect is not due to a decrease in the level of histone H3 lysine 56 acetylation. Intriguingly, mutations that alter the sites of newly synthesized histone H4 acetylation display a marked decrease in levels of phosphorylated H2A (γ-H2AX) in chromatin surrounding the double-strand break. These results indicate that the sites of acetylation on newly synthesized histones H3 and H4 can function in nonoverlapping ways that are required for chromatin assembly, viability, and DNA damage response signaling.

scholarly journals Schizosaccharomyces pombe KAT5 contributes to resection and repair of a DNA double strand break

Genetics ◽  
2021 ◽  
Author(s):  
Tingting Li ◽  
Ruben C Petreaca ◽  
Susan L Forsburg
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Chromatin Remodeling ◽  
Dna Damage Response ◽  
Histone Acetyltransferase ◽  
Strand Break ◽  
Double Strand Break ◽  
Dna Damage Checkpoint ◽  
Dna Double Strand Break ◽  
Damage Response

Abstract Chromatin remodeling is essential for effective repair of a DNA double strand break. KAT5 (S. pombe Mst1, human TIP60) is a MYST family histone acetyltransferase conserved from yeast to humans that coordinates various DNA damage response activities at a DNA double strand break (DSB), including histone remodeling and activation of the DNA damage checkpoint. In S. pombe, mutations in mst1+ causes sensitivity to DNA damaging drugs. Here we show that Mst1 is recruited to DSBs. Mutation of mst1+ disrupts recruitment of repair proteins and delays resection. These defects are partially rescued by deletion of pku70, which has been previously shown to antagonize repair by homologous recombination. These phenotypes of mst1 are similar to pht1-4KR, a non-acetylatable form of histone variant H2A.Z, which has been proposed to affect resection. Our data suggest that Mst1 functions to direct repair of DSBs towards homologous recombination pathways by modulating resection at the double strand break.

scholarly journals RUNX Family Participates in the Regulation of p53-Dependent DNA Damage Response

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Toshinori Ozaki ◽  
Akira Nakagawara ◽  
Hiroki Nagase
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Cell Cycle Arrest ◽  
Dna Damage Response ◽  
Apoptotic Cell ◽  
Genetic Alterations ◽  
Apoptotic Cell Death ◽  
Cycle Arrest ◽  
Damage Response

A proper DNA damage response (DDR), which monitors and maintains the genomic integrity, has been considered to be a critical barrier against genetic alterations to prevent tumor initiation and progression. The representative tumor suppressor p53 plays an important role in the regulation of DNA damage response. When cells receive DNA damage, p53 is quickly activated and induces cell cycle arrest and/or apoptotic cell death through transactivating its target genes implicated in the promotion of cell cycle arrest and/or apoptotic cell death such asp21WAF1,BAX, andPUMA. Accumulating evidence strongly suggests that DNA damage-mediated activation as well as induction of p53 is regulated by posttranslational modifications and also by protein-protein interaction. Loss of p53 activity confers growth advantage and ensures survival in cancer cells by inhibiting apoptotic response required for tumor suppression. RUNX family, which is composed of RUNX1, RUNX2, and RUNX3, is a sequence-specific transcription factor and is closely involved in a variety of cellular processes including development, differentiation, and/or tumorigenesis. In this review, we describe a background of p53 and a functional collaboration between p53 and RUNX family in response to DNA damage.

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