scholarly journals DYNLL1 mis-splicing is associated with replicative genome instability in SF3B1 mutant cells

2021 ◽  
Author(s):  
Annie S Tam ◽  
Shuhe Tsai ◽  
Emily Yun-Chia Chang ◽  
Veena Mathew ◽  
Alynn Shanks ◽  
...  
Keyword(s):  
Dna Repair ◽  
Genome Stability ◽  
Genome Instability ◽  
Parp Inhibitor ◽  
Mutant Cell ◽  
Gene Mutations ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Loop Formation ◽  
Cancer Hallmarks

Genome instability is a hallmark of cancer that arises through a panoply of mechanisms driven by oncogene and tumour-suppressor gene mutations. Oncogenic mutations in the core splicing factor SF3B1 have been linked to genome instability. Since SF3B1 mutations alter the selection of thousands of 3' splice sites affecting genes across biological pathways, it is not entirely clear how they might drive genome instability. Here we confirm that while R-loop formation and associated replication stress may account for some of the SF3B1-mutant genome instability, a mechanism involving changes in gene expression also contributes. An SF3B1-H662Q mutant cell line mis-splices the 5'UTR of the DNA repair regulator DYNLL1, leading to higher DYNLL1 protein levels, mis-regulation of DNA repair pathway choice and PARP inhibitor sensitivity. Reduction of DYNLL1 protein in these cells restores genome stability. Together these data highlight how SF3B1 mutations can alter cancer hallmarks through subtle changes to the transcriptome.

scholarly journals NME3 Regulates Mitochondria to Reduce ROS-Mediated Genome Instability

2020 ◽  
Vol 21 (14) ◽  
pp. 5048
Author(s):  
Chih-Wei Chen ◽  
Ning Tsao ◽  
Wei Zhang ◽  
Zee-Fen Chang
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Genome Stability ◽  
Nuclear Dna ◽  
Genome Instability ◽  
Mitochondrial Fission ◽  
Nucleoside Diphosphate Kinase ◽  
Mitochondrial Fusion ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Oxidative Stress

NME3 is a member of the nucleoside diphosphate kinase (NDPK) family that binds to the mitochondrial outer membrane to stimulate mitochondrial fusion. In this study, we showed that NME3 knockdown delayed DNA repair without reducing the cellular levels of nucleotide triphosphates. Further analyses revealed that NME3 knockdown increased fragmentation of mitochondria, which in turn led to mitochondrial oxidative stress-mediated DNA single-strand breaks (SSBs) in nuclear DNA. Re-expression of wild-type NME3 or inhibition of mitochondrial fission markedly reduced SSBs and facilitated DNA repair in NME3 knockdown cells, while expression of N-terminal deleted mutant defective in mitochondrial binding had no rescue effect. We further showed that disruption of mitochondrial fusion by knockdown of NME4 or MFN1 also caused mitochondrial oxidative stress-mediated genome instability. In conclusion, the contribution of NME3 to redox-regulated genome stability lies in its function in mitochondrial fusion.

Detection of HRD gene mutations and copy number changes in cfDNA from prostate cancer patients.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e16546-e16546
Author(s):  
Chris Raymond ◽  
Jenny Hernandez ◽  
Reynolds Brobey ◽  
Yue Wang ◽  
Kristy Potts ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Copy Number ◽  
Genome Instability ◽  
Parp Inhibitor ◽  
Gene Mutations ◽  
Gene Copy ◽  
Deleterious Mutations ◽  
Castration Resistant Prostate Cancer ◽  
Brca1 Brca2 ◽  
Copy Number Changes

e16546 Background: Recent genomic surveys of prostate cancer have identified somatic mutations in metastatic castration-resistant prostate cancer (mCRPC). In this study, we examined mCRPC patients for AR aberrations and mutations in the HRD (homologous recombination DNA-repair) pathway which may confer platinum or PARP inhibitor sensitivity. Methods: A novel targeted-hybrid-capture NGS assay capable of identifying deleterious mutations, copy number amplification and gene copy loss, was applied to circulating, cell-free DNA (cfDNA) extracted from plasma samples from 20 mCRPC patients. Samples were collected between 3/2010 – 10/2015 and stored at -20C. The gene panel used in the assay included AR and several genes in the HRD pathway — ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, HDAC2, NBN, PALB2, and RAD51. Sequencing libraries created with the cfDNA extracted from 2.8-4 mLs of plasma had an average unique read coverage depth of 2282 genome equivalents (range 445 – 5136, median 2181). Results: Somatic variations were observed in 17 of the 20 samples analyzed. Copy number variation (CNV) was observed in 11 samples. AR amplification, linked to resistance to abiraterone and enzalutamide, was observed in 30% (6) of samples. Canonical AR ligand binding domain mutations, such as T787A and L702H were also detected. ATM, BRCA1, BRCA2, HDAC2, and FANCA gene deletions were also detected, as well as frameshift, nonsense, and other deleterious mutations in HRD genes. Significant CNV in multiple genes was observed in at least 5 patient samples. Mutations were detected across the entire collection date range, speaking to the robustness of cfDNA. Conclusions: Non-invasive tumor mCRPC genotyping appears to be feasible. The ability to detect HRD gene alterations suggests cfDNA testing may be suitable for the detection of HRD pathway defects and overall genome instability.

Randomized phase II study of second-line modified FOLFIRI with PARP inhibitor ABT-888 (Veliparib) (NSC-737664) versus FOLFIRI in metastatic pancreatic cancer (mPC): SWOG S1513.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 4014-4014 ◽  
Author(s):  
E. Gabriela Chiorean ◽  
Katherine A Guthrie ◽  
Philip Agop Philip ◽  
Elizabeth M. Swisher ◽  
Florencia Jalikis ◽  
...  
Keyword(s):  
Dna Repair ◽  
Phase Ii ◽  
Somatic Mutations ◽  
Phase Ii Study ◽  
Parp Inhibitor ◽  
Gene Mutations ◽  
Control Treatment ◽  
Repair Gene ◽  
Randomized Phase Ii ◽  
Dna Repair Gene

4014 Background: PC is characterized by DNA Damage Repair (DDR) deficiencies, including in BRCA1/2, ATM, and FANC genes. Given preclinical synergism between veliparib with irinotecan, safety and preliminary efficacy, we designed a randomized phase II study of mFOLFIRI (no 5-FU bolus) + veliparib vs FOLFIRI alone for 2nd line mPC patients (pts). Methods: Eligible pts had mPC, adequate organ function, ECOG PS 0-1, and 1 prior non-irinotecan systemic therapy.143 pts were to be randomized (1:1) to veliparib vs control. Primary endpoint was overall survival (OS). All pts had blood and tumor biopsies at baseline to assess germline and somatic BRCA1/2 mutations (integrated), and homologous recombination (HR) or DDR biomarkers (exploratory). Results: 123 pts were accrued between 09/2016 to 12/2017, and 108 were included in this analysis. 117 pts were biomarker evaluable: 109 blood/106 tumors. 11 cancers (9%) had HR deficiency (HRD), including 4 germline ( BRCA1, BRCA2, ATM) and 7 somatic mutations ( BRCA2, PALB2, ATM, CDK12). Additional 24 cancers (20%) had germline (n = 11, e.g., FANC, BLM, SLX4, CHEK2) or somatic mutations (n = 13, e.g., FANC, BLM, POLD1, RIF1, MSH2, MSH6) in other DNA repair genes, not classified as HRD. A planned interim futility analysis at 35% of expected PFS events determined the veliparib arm was unlikely to be superior to control. Most common grade 3/4 treatment related toxicities were neutropenia (33% vs 20%), fatigue (19% vs 4%), and nausea (11% vs 4%), for veliparib vs control. Treatment exposure was similar for veliparib vs control: median 4 cycles (range 1-31 vs 1-32). Median OS was 5.1 vs 5.9 mos (HR 1.3, 95%CI 0.9-2.0, p = 0.21), and median PFS was 2.1 vs 2.9 mos (HR 1.5, 95%CI 1.0-2.2, p = 0.05) for veliparib vs control arms, respectively. Correlations of gene mutations and signatures with efficacy outcomes will be presented. Conclusions: Nearly 30% of mPC pts had DNA repair gene abnormalities, including 9% with HRD. Veliparib increased toxicity and did not improve OS when added to mFOLFIRI in biomarker unselected pts. BRCA1/2 and DDR biomarkers will be correlated with efficacy to inform patient selection for future PARP inhibitor clinical trials. Clinical trial information: NCT02890355.

p53 Tumour Suppressor Gene Mutations in Benign Prostatic Hyperplasia and Prostate Cancer

1998 ◽  
Vol 34 (5) ◽  
pp. 433-440 ◽  
Author(s):  
Horst Schlechte ◽  
Severin V. Lenk ◽  
Thomas Löning ◽  
Dietmar Schnorr ◽  
Birgit D. Rudolph ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Benign Prostatic Hyperplasia ◽  
Gene Mutations ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Prostatic Hyperplasia ◽  
Tumour Suppressor ◽  
P53 Tumour Suppressor Gene

scholarly journals Relationship between TP53 tumour suppressor gene mutations and smoking-related bulky DNA adducts in a lung cancer study population from Hungary

Mutagenesis ◽  
2009 ◽  
Vol 24 (6) ◽  
pp. 475-480 ◽  
Author(s):  
Lívia Anna ◽  
Reetta Holmila ◽  
Katalin Kovács ◽  
Erika Győrffy ◽  
Zoltán Győri ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Dna Adducts ◽  
Gene Mutations ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Tumour Suppressor ◽  
Cancer Study ◽  
Study Population ◽  
Bulky Dna Adducts

scholarly journals The Relevance of G-Quadruplexes for DNA Repair

2021 ◽  
Vol 22 (22) ◽  
pp. 12599
Author(s):  
Rebecca Linke ◽  
Michaela Limmer ◽  
Stefan Juranek ◽  
Annkristin Heine ◽  
Katrin Paeschke
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Genome Stability ◽  
Genome Instability ◽  
Genetic Disorders ◽  
Telomere Maintenance ◽  
Dna Structures ◽  
G4 Dna ◽  
G Quadruplex ◽  
Repair Pathways

DNA molecules can adopt a variety of alternative structures. Among these structures are G-quadruplex DNA structures (G4s), which support cellular function by affecting transcription, translation, and telomere maintenance. These structures can also induce genome instability by stalling replication, increasing DNA damage, and recombination events. G-quadruplex-driven genome instability is connected to tumorigenesis and other genetic disorders. In recent years, the connection between genome stability, DNA repair and G4 formation was further underlined by the identification of multiple DNA repair proteins and ligands which bind and stabilize said G4 structures to block specific DNA repair pathways. The relevance of G4s for different DNA repair pathways is complex and depends on the repair pathway itself. G4 structures can induce DNA damage and block efficient DNA repair, but they can also support the activity and function of certain repair pathways. In this review, we highlight the roles and consequences of G4 DNA structures for DNA repair initiation, processing, and the efficiency of various DNA repair pathways.

scholarly journals Genome instability and loss of protein homeostasis: converging paths to neurodegeneration?

Open Biology ◽  
2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Anna Ainslie ◽  
Wouter Huiting ◽  
Lara Barazzuol ◽  
Steven Bergink
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Neurodegenerative Diseases ◽  
Genome Stability ◽  
Genome Instability ◽  
Copy Number Variations ◽  
Therapeutic Interventions ◽  
Gene Copy ◽  
Protein Homeostasis ◽  
Age Related

Genome instability and loss of protein homeostasis are hallmark events of age-related diseases that include neurodegeneration. Several neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis are characterized by protein aggregation, while an impaired DNA damage response (DDR) as in many genetic DNA repair disorders leads to pronounced neuropathological features. It remains unclear to what degree these cellular events interconnect with each other in the development of neurological diseases. This review highlights how the loss of protein homeostasis and genome instability influence one other. We will discuss studies that illustrate this connection. DNA damage contributes to many neurodegenerative diseases, as shown by an increased level of DNA damage in patients, possibly due to the effects of protein aggregates on chromatin, the sequestration of DNA repair proteins and novel putative DNA repair functions. Conversely, genome stability is also important for protein homeostasis. For example, gene copy number variations and the loss of key DDR components can lead to marked proteotoxic stress. An improved understanding of how protein homeostasis and genome stability are mechanistically connected is needed and promises to lead to the development of novel therapeutic interventions.

scholarly journals Preimplantation diagnosis for p53 tumour suppressor gene mutations

2001 ◽  
Vol 2 (2) ◽  
pp. 102-105 ◽  
Author(s):  
Yury Verlinsky ◽  
Svetlana Rechitsky ◽  
Oleg Verlinsky ◽  
Kangu Xu ◽  
Glenn Schattman ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Tumour Suppressor ◽  
Preimplantation Diagnosis ◽  
P53 Tumour Suppressor Gene

scholarly journals DNA repair goes hip-hop: SMARCA and CHD chromatin remodellers join the break dance

2017 ◽  
Vol 372 (1731) ◽  
pp. 20160285 ◽  
Author(s):  
Magdalena B. Rother ◽  
Haico van Attikum
Keyword(s):  
Dna Repair ◽  
Posttranslational Modifications ◽  
Chromatin Structure ◽  
Hip Hop ◽  
Genome Stability ◽  
Genome Instability ◽  
Current Knowledge ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

Proper signalling and repair of DNA double-strand breaks (DSB) is critical to prevent genome instability and diseases such as cancer. The packaging of DNA into chromatin, however, has evolved as a mere obstacle to these DSB responses. Posttranslational modifications and ATP-dependent chromatin remodelling help to overcome this barrier by modulating nucleosome structures and allow signalling and repair machineries access to DSBs in chromatin. Here we recap our current knowledge on how ATP-dependent SMARCA- and CHD-type chromatin remodellers alter chromatin structure during the signalling and repair of DSBs and discuss how their dysfunction impacts genome stability and human disease. This article is part of the themed issue ‘Chromatin modifiers and remodellers in DNA repair and signalling’.

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